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REFORT 



OF 



BOARD OF ENGINEERS 



ON 



STEEL PORTLAND CEMENT 



AS USED IN 



UNITRD STATES LOCK AT PLAQUKMINE. I,A, 




Washington : 

(ioVKKNMKNT J*RINTIN(I Ol-'FIL'K. 
1900. 



U>S, R-ryr^sj , C.OVDS ci- a-n^ iV^ ecr S / 




REPORT 



OF 



BOARD OF ENGINEERS 



ON 



C G 



/i ~C 



STEEL PORTLAND CEMENT 



AS USED IX 



UNITED STATES LOCK AT PLAQUEMiXE, LA. 



Washington: 

GoVEltNMKNT PriNTIN<J OfFICE. 

1900. 



X 






Document Ko. 119. 
Office of the Chief of Exgixeers 



iWAr 18 lyoa 



[Eighth indorsement.] 

Office, Chief of Engineers, 

U. S. Army, 

April 18, 1900. 

Respectfully returned to the Secretary of War, inviting attention 
to the able and exhaustive report of the Board of Engineer Officers 
appointed under the authority of the Secretary of War, contained in 
the fifth indorsement, to consider and report upon the use of Steel 
Portland cement in the lock at Plaquemine, La. 

:]« Hi ^ H: Ht H< ^ 

In view of the great value to the engineering profession of this 
able and thorough investigation, I have further to recommend that 
authority be granted to have the report of the Board printed at the 
Government Printing Office, and that 500 copies be obtained for the 
use of the Engineer Department, upon the usual requisition. 

John M. Wilson, 
Brig. Gen., Chief of Engineers, 

U. S. Aruiy. 



[Ninth indorsement.] 

War Department, 

3Iay 5, 1900. 

The recommendations of tlie Cliief of Engineers, contained in the 

eighth indorsement hereon, are approved. 

Elihu Root, 

Secretary of War. 
(3) 



REPORT OF BOARD OF ENGINEERS ON "STEEL PORTLAND 
CEMENT" AS USED IN UNITED STATES LOCK AT PLAQUE- 
MINE, LA. 



New Orleans, La., 

JIarch 30, 1900. 

General: The Board of Engineers convened by paragraph 2, 
Special Orders, No. 10, Headquarters, Corps of Engineers, U. S. 
Army, dated Washington, Marcli 1, 1900, has the honor to submit 
the following report : 

The order convening the Board was as follows : 

Headquarters, Corps of Engineers, 
United States Army, 

Washington, March 1, lUOO. 



Special Orders, / 

No. 10. [ 



\Extract.'\ 



2. By authority of the Secretary of War, a Board of Officers of tlie Corps of 
Engineers, to consist of — 

Major William L. Mar sJ tall, 
Major Willia^n H. Bixhy, 
Capt. Charles S. Riche. 

will assemble at New Orleans, La., upon the call of the Senior Member, to con- 
sider and report upon the use of Steel Portland cement in the lock at Placjue- 
mine. La. 

Upon the completion of tlie duty assigned them, the members of the Board 
will return to their i)roper stations. 

The Board is authorized to visit such points as it deems necessary for the 
proper performance of its duties. 

The journeys re(iuired under this order are necessary for the public service. 

By command of Brig. Gen. Wilson : 

Joseph E. Kihn, 

('(iptditi. Corps of EiKjiut CIS. 

There was referred to the Board a letter to the llonorabh' the 
Sec'retary of War from Mr. Charles Mac \'eagli, (hited \ew YoiU, 
K(^l)i'uary 15, 1 !)()(), tlu^ sixth iiidoi'stMuent on wliich \c\ivi' was as 
I'oUows: 

(5) 



6 

[Sixth indorsement.] 

Office, Chief of Engineers, 

U. S. Army, 
Ilarch 1, 1900. 

Respectfully referred to Major W. L. Marshall, President of the Board of 
Engineer Officers, constituted by paragraph 2, Special Orders, No. 10, Headquar- 
ters, Corps of Engineers, current series. 

The Board is requested to visit the Plaquemine lock, carefully examining the 
work done to date, and the works of the Illinois Steel Company, where the details 
of the manufacture of Steel Portland cement will be thoroughly investigated and 
the officials of the company given full opportunity to present their views relative 
to the quality of their product and the propriety of its use upon important engi- 
neering works. 

As early a report as practicable is desired. 
By command of Brig. Gen. Wilson : 

Jas. L. Lusk, 
** Major, Corps of Engineers. 

The following letter was also received from Headquarters, Corps 

of Engineers : 

Headquarters, Corps of Engineers, 

United States Army, 

Washington, March 5, 1900. 
Major : Referring to paragraph 2, Special Orders, No. 10, current series, from 
these headquarters, and to instructions contained in Department indorsement of 
March 1, 1900, I am directed by the Chief of Engineers to inform you that the 
Board is authorized to visit the works of the Illinois Steel Company at Chicago, 
111., before proceeding to New Orleans, La. 

Very respectfully, your obedient servant, 

Joseph E. Kuhn, 

Captain, Corps of Engineers. 
Maj. William L. Marshall, 

Corps of Engineers, 

Senior Member, Board on Steel Portland Cement, 

New York City. 

In accordance with the foregoing orders and instructions, the fol- 
lowing order was issued by the president of the Board : 

United States Engineer Office, 
Room H 7, Army Building, 39 Whitehall Street, 

New York City, March 9, 1900. 
The Board of Engineer Officers, constituted by Special Orders, No. 10, para- 
graph 2, Headquarters, Corps of Engineers, U. S. Army, Washington, D. C, 
March 1, 1900, will assemble at the U. S. Engineer Office, 1637 Indiana avenue, • 
Chicago, 111., on Monday, March 19, 1900, at 10 o'clock, a. m. 
The travel enjoined is necessary for the public service. 

W. L. Marshall, 
Major, Corps of Engineers, 

Pr^ident of the Board. 

In accordance with the above, the Board met in Chicago at 10 
o'clock, a. m., March 19, 1900. 



ITINERARY. 

In company witli officials of the Illinois Steel Company the Board on 
March 19, 1900, visited the North Works of said company in Chicago, 
and inspected the factory where the "Steel Portland Cement " was in 
process of manufacture and also the cement-testing laboratory at said 
works. Several samples of concrete, in which it was stated that this 
cement had been used, were also examined. 

The officials of the company informed the Board that one of the 
earliest structures in which their cement had been used was a con- 
crete abutment of the Cascade Highway Bridge, in Burlington, Iowa, 
which had been erected in 1896 and had been exposed to the air since 
then. The Board deemed it necessary to inspect this abutment and, 
in accordance with the authorit}^ given it by paragraph 2, Special 
Orders, No. 10, Headquarters, Corps of Engineers, Washington, D. C, 
dated March 1, 1900, it left Chicago on March 19, 1900, and proceeded 
to Burlington, Iowa, where it' inspected the above-mentioned abut- 
ment on March 20, 1900, and returned to Chicago on the same day. 

The South Works of the Illinois Steel Company being located at 
South Chicago, the Board, in order fully to comply with its instruc- 
tions, proceeded on March 21, 1900, to South Chicago, where it in- 
spected the company's plant for producing and granulating the slag 
for use in manufacturing its cement. The Board also inspected the 
new and larger cement factory which the company is erecting at its 
South Works. The Board also examined a number of concrete foun- 
dations and other structures which had been erected by the company 
for its use at its South Works and in which officials of the company 
stated that its cement had been used. After completing its inspec- 
tion the Board returned to Chicago. 

On March 21, 1900, the Board left Chicago for New Orleans, La. , and 
arrived at the latter place on March 22, 1900. On March 23, 1900, 
the Board proceeded to Plaquemine, La., where it made a careful 
examination of the work already done on the Government lock and 
of the laboratory where the cement was inspected and tested. 

On Marcli 24, 1900, the Board returned to New Orleans, La., having 
been accompanied in all of its inspections and journeys up to this 
time by the president, consulting engineer, attorney, and otluM- rep- 
res(5ntatives of the Illinois Steel Company. 

These represc^itativc^s, not wishing to a('Com[)aiiy the i>oard in its 
furtlier inspections, left New Orleans for Chicago on Marcli 21, 1900, 
and, on Marcli 25, 1900, the Board proceeded to Forts St. Philip and 
Jackson, where some of tlie Illinois Steel Company's cement had been 
used in tlic fori ideations. After exaniinini>- the conci-eh^ made I'l-oui 



8 

this cement and comparing it with adjacent concrete and mortar 
made from other cements, the Board returned to New Orleans, arriv- 
ing there on March 26, 1900. Thereafter, meetings of the Board 
were held in the United States Engineer Office, Customhouse, New 
Orleans, La. 

PROCESS OF MANUFACTURE OF ILLINOIS STEEL COMPANY'S CEMENT. 

With regard to the manufacture of the " Steel Portland Cement" 
by the Illinois Steel Company, the investigations of the Board showed 
that it was substantially as described by Mr. Jasper Whiting, the 
manager of their cement department, in his letter of March 16, 1900, 
to the president of the companj^ a copy of which is forwarded here- 
with as Inclosure 2 of Appendix 1. 

A copy of the specification forming part of the letters patent cov- 
ering this process is also forwarded herewith as Inclosui-e 1 of Aj)- 
pendix 2. 

In brief, this cement is granulated slag pulverized and mixed 
mechanically with hydrates of lime, with the addition of a little soda 
to diminish the time of setting of the resultant cement ; but, with the 
exception of the addition of soda, the process is substantialh^ the same 
as that described in "Ciments. et ChauxHydrauliques," b}^ Candlot, 
published in 1891 (Appendix 7, herewith), and in "Le Beton et Son 
Emploi," by Mahiels, published in 1893 (Appendix 8, herewith). 

The Board carefullj^ examined the process of manufacture of the 
*' Steel Portland Cement" aiid the records of such manufacture and 
of the chemical analyses to which the ores, slag, limestone, and 
cement are regularly subjected. The Illinois Steel Company pos- 
sesses exceptional facilities for this manufacture by reason of the 
remarkably uniform ores and other materials which it uses and by 
reason of the size of its plant and the number of its blast furnaces, 
a few of which may be specially devoted to the production of slag 
for cement manufacture. All these circumstances permit the eco- 
nomical production of a specially suitable basic slag. As a result, 
the company is able to produce a cement of great uniformity. This 
uniformity, in addition to the extreme fineness to which the cement 
is ground, leads the Board to believe that the Illinois Steel Company's 
cement is superior to anj^ slag or puzzolana cement of which the 
Board has been able to obtain record. 

DESCRIPTION OF PRODUCT AND COMPARISON WITH PORTLAND 
CEMENTS AND SLAG CEMENTS. 

The following table shows the limiting percentages of the constitu- 
ents of the Illinois Steel Company's cement, of a number of samples 
of European slag cements, and of Portland cements : 



9 

TABLE OF ANALYSES. 

ILLINOIS STEEL COMPAXY-S CEMENT. 
[See Exhibit P of Inclosure 2 of Appendix 1, herewith.] 



Minimum. Maximum. 



Silica 27. 80 29. 90 

Alumina and iron 11.10 13.00 

Lime 50. 29 52. li 

Magnesia 1. 58 2. 96 

Sulphur 1. U 1. 48 

Loss on ignition 2. 60 5. 50 

EUROPEAN SLAG CEMENTS. 
[As obtained from Candlot and Tetmajer and given also in Spalding's ''Hydraulic Cement.'"] 

Silica !. 18.1 27.5 

Alumina 9. 1 19. 1 

Iron oxide 0. 3 2. 8 

Lime 30. (j 55. 6 

Magnesia 0. 5 6.8 

Sulphuric acid 0.1 2.7 

Loss on ignition 2. U 12. 2 

PORTLAN'D CEMENTS. 
[As obtained from Candlot and Spalding. J 

Silica 20 25 

Alumina 5 9 

Iron oxide 2 5 

Lime 57 65 

Magnesia 0.5 2 

Sulphuric acid 0. 25 1 1. 50 

Loss on ignition 0. 25 i 5. 40 



From the above table it will be noted that the Illinois Steel Com- 
pany's cement as well as European slag cements contain veiy materi- 
ally more silica and alumina and veiy materiall}^ less lime than Port- 
land cements. It will also be noted that the loss by ignition is usually 
greater for the first-named cements than for Portland cements. 

The Board was informed by representatives of the Illinois Steel 
Company that the specific gravity of their cement was about '2.8. 
This is the specific gravity given for their cement in Exhibit G* of 
Inclosure 2 of Api^endix 1, herewith. From numerous authorities the 
l>oai'd finds that the specific gravity of Portland cements varies from 
3.0 to 3.5 and usually from 3.1 to :).18, and of slag cements in gen- 
eral the specific gravity is from 2.7 to 2.S. 

All authorities consulted by the lioard agree that in Portland 
(Himenls sulphur exists mainly in the form of sid])hatt^s (usually the 
sul[)hate of lime, added tluM'eto for the [)urpose of controlling the 
setting), wherc^as in slag cements it exists in the form of sul[)hido.s, 
to which is due the greenish tint whicli slag-cement mortars and con- 

* Not printed. 



10 

Crete acc[uire when kept under water. All of the concrete examined 
by the Board and which, had been made from the Illinois Steel Com- 
pany's cement and had been kept in moist condition, showed this 
characteristic color to a marked degree. The injurious effects of 
sulphates and sulphides upon cements are discussed in a number of 
the appendixes to this report. 

The Illinois Steel Company's cement when mixed stiff either neat 
or with sand and thoroughly compacted into molds to form briquettes, 
and kept in water after tAventy-four hours have elapsed from the 
time of molding, shows results for tensile strength and for sand- 
carrying capacity fully equal to the best Portlands, and such bri- 
quettes also exhibit great hardness. (Appendixes 1 and 4 herewith.) 
Prominent European writers report similar results from briquettes 
of European slag cements when made in the same way, but add that 
when these briquettes are made of mo]'tar of ordinary working con- 
sistency they do not ultimately become nearly so hard or so strong. 

The Board has not been able to obtain the results of any tests of 
the Illinois Steel Company's cement briquettes mixed of ordinary 
working consistency, but wherever it examined mortar and concrete 
made from this cement, and found the product hard, the latter had 
evidently been thorotighly com^^aeted when laid. Except in such 
cases, which were few, the examinations l)y the Board of the mortar 
and concrete made from this cement showed that the results were 
not nearly equal in strength and hardness to those obtained from 
Portland cement mortar and concrete of ordinary quality. The Board, 
however, found that concrete made from the Illinois Steel Company's 
cement, when in masses where it had been kept fairly moist, exhib- 
ited exceptional toughness and that layers of this concrete which had 
been placed on different days had united into an aiDparently homo- 
geneous mass without any evidence of planes of weakness between 
the layers. These two qualities of totighness and thorough union of 
adjacent layers are more marked in the Illinois Steel Company's 
cement than in Portland cements. 

The Board has also been unable to obtain the results of any tests 
of the Illinois Steel ComiDany's cement when made into briquettes 
and kept in dry air after setting. The majority of the structures in 
which this cement has been used have been foundations or other 
structures in moist i^laces. Xearly all atithorities on slag cements 
agree that these cements are tinsuitable for use where exposed to dry 
air or to mechanical wear, on account of their liability to crack or 
crumble at the surface, whereas Portland cements are eminently 
suitable for such exposure. Except where evidently compacted with 
unusual care when laid, the Illinois Steel Company's cement mortar 



11 

and concrete wherever exposed to air were found to be much inferior 
in strength and hardness to similar mixtures made from Portland 
cements. 

In this connection, attention is invited to Inclosure 2 of Appendix 
2, herewith, where, in a letter to Maj. H. M. Adams, the manager 
of the cement department of the Illinois Steel Company states that 
in the companj^'s pam]3hlets advertising its cement it admitted to a 
certain extent that its cement was not suitable for all classes of work, 
notably exposed work in dry air. He also states that the company 
has never represented its cement to be a sidewalk cement or a cement 
suitable for use in thin layers where the material is exposed to the 
drying influence of the atmosphere. 

From the method of manufacture of slag cements there should be 
no uncombined nor unslaked lime in the finished product, and since 
slag cement is dependent for its activity upon the slaked lime mixed 
with its slag, and as this slaked lime soon becomes carbonized and 
inert by contact with the atmosphere, it is jjracticable and advanta- 
geous that slag cement should be used as soon as possible after its 
manufacture. Portland cement on the contrary maj^be kept indefi- 
nitely in dry air without deterioration, and often with advantage. 
Where the Illinois Steel Company's cement is used, it should be 
used as soon as possible after it is manufactured, in order that the 
capacity of its soda to hasten its time of setting may not be reduced 
and in order that its slaked and uncombined lime may not become 
carbonized and inert from exposure to the air. 

According to all reports, slag cements, while needing considerable 
water for properly tempering the mortar, will only combine chemic- 
ally and permanently with a very small percentage of water, say 
about 5 per cent, and will not set compactly wlien tempered with a 
very large quantity of water. While thus reqttiringbut little water, 
the slag cements require it continuously and for a long time. On the 
contrary, the Portland cements combine chemically and permanently 
with three or four times as much water as the slag cements, and will 
set compactly when tempered with so much water as to produce com- 
parativel}^ a thin paste, and in sotting will shed the excess water. 
Cons(Mtuenliy if the slag cements be mixed with the anu)unt of 
water needed for X)roj)er tempering, their mortar and concM'ete may 
later become porous and weak by the ultimate eva])orati()ii of the 
excess water. As a rcsnll, the slag cements re(iuii-e a much more 
carciful workmanship than the INn'llaiul cements, ami IhiMr use in 
ordinai'y con('i'(^te is conseciuently much more risky. The IJoard does 
not believe that a slag-cemcMit concrete can lu' made wilii a hai'd and 
dense textui'e without limiting tiie amount of water in temixM'ing to 



12 

the least amount that will allow of cousolidation ; that is. to as near 
as practicable the amount needed for final chemical combination, 
then comx^acting the mortar or concrete prior to and during its set 
much more thoroughly than in the case of Portland cements, and 
thereafter keeping it constantly supplied with moisture until the set- 
ting is entirely completed. 

STEUCTURES EXAMINED. 

In making its investigations the Board examined the concrete made 
from the Illinois Steel Company's cement and the brick masonry laid 
in mortar made from this cement and used for foundations foi* its 
heav}' machinery, at its Xorth and South Works in Chicago, some of 
this concrete in its new cement factory being under construction at 
the time of the Board's examination. An experimental sewer, built 
of this concrete at the Xorth "^Vorks for the purpose of ascertaining 
how it would be affected by winter temperatures, was also examined. 
A small experimental tank of the Monier construction at the South 
Works was also examined. This tank, reported to have been in 
place for about three years, was found to be in specially good condi- 
tion, probably due to its special construction and to careful work- 
manshi]3. 

The Board also examined an abutment of the Cascade Highway 
Bridge at Burlington. Iowa, which was built about three years and 
nine months ago of the Illinois Steel Company's cement. This abut- 
ment showed evidences of irregular workmanship, but is well fulfill- 
ing the purpose for which it was constructed. 

The Board also examined the two 15-pounder batteries at Forts 
St. PhiliiD and .lackson. La., constructed about eleven months ago of 
the Illinois Steel Company's cement and surfaced or plastered with 
Portland cement. A careful comparison was here made between 
these works and those constructed of other cements, both natural 
and Portland, all of which have been subjected to the same sur- 
roundings and conditions. It was reported to the Board that a small 
XDiece of sidewalk made at Fort Jackson from the Illinois Steel Com- 
pany's cement had soon cracked and become unfit for its purpose 
and had been replaced by a pavement made from Portland cement. 

The Board also examined the concrete work at the Government 
lock at Plaquemine. La., made from the Illinois Steel Company's 
cement between July, 1899. and February. 1900. This concrete 
apx)ears to have been very carefully mixed, deposited, and rammed, 
but its surfacing on exposed vertical faces was soft and of chalk- 
like texture, unsuited to resist mechanical wear. The concrete below 
the level of the lock floor was in place and the lock walls had been 
built to a level several feet above the lock floor. The wing walls at 



13 

each end of the lock had been built to a somewhat higher level. 
Some sample pieces of concrete which liad been exposed to atmos- 
pheric influences for about eight or nine months were also examined, 
and some briquettes and pats were made for the Board from some of 
the Illinois Steel Company's cement wiiich had been in store at 
Plaquemine for about six w-eeks. 

The North Works foundations, the experimental sewer at the same 
locality, the Burlington bridge abutment, and the concrete at Plaque- 
mine were examined bj^ the aid of picks and drills. The lo-pounder 
batteries at Forts St. Philip and Jackson had previously been exam- 
ined in this manner b}^ the junior engineer in local charge of these 
works. 

All the concrete inspected by the Board presented the general char- 
acteristics of a first-class slag-cement concrete. Some of it was 
exceedingly tough and resisted the pick with great success; but in 
strength, close texture, and flinty hardness and fracture none of it 
appeared equal to first-class Portland-cement concrete. 

At Forts St. Philip and Jackson a direct comparison between the 
Illinois Steel Company's cement and some American and German Port- 
land cements, used for jjlastering and pavements, showed plainly the 
superiority of the latter cements. Tlie concrete at Plaquemine and 
at Forts St. Philip and Jackson was made with gravel, and in all this 
gravel concrete it was noticed that the pebbles w^ere easily separated 
from the surrounding mortar in spite of the general toughness of the 
concrete. The Board has not found this result with equally rich 
gravel concrete made from Portland cement. In the case of the Illi- 
nois Steel Company's cement concrete made from crushed rock, and 
in the case of brickwork laid in mortar made from this cement, the 
rock and brick sometimes broke instead of separating from the 
mortar, but this mortar' in botli cases gave many evidences of less 
adhesive and cohesive strength than would be exhibited by l^ortland- 
cement mortar of equal richness. Where\'er tlie Illinois Steel Com- 
pany's cement mortar was laid loosely without i)ressure it was found 
after setting to be weak and pulverulent, wliereas l^ortland-cement 
moi'tars of equal richness and good quality under similar conditions 
are invariably found to be hard and strong. 

DEFINITIONS. 

As the Illinois and l'\'d(M-aI Steel Companies, by the letter of tluMr 
counsel, Cliarles Mac \'eagh, to the Secretai'y of War, under date of 
February IT), lOOO, which letter was referred to the Uoai'd by sixth 
indorsement above (juoted, have specifically re(iuested an investiga- 
tion "to ase(M'tain whethei- 'Steel Portland CcMuiMit ' is a hii:h-uTnde 



14 

American Portland within the meaning of the specifications in ques- 
tion," the Board has made special investigations as to the classifica- 
tion of such cements by European and American scientific bodies, 
cement manufacturing and commercial associations, and technical 
text books. 

The most authoritative classification of cementing substances in 
general found by the Board is that of the International Convention 
for the Unification of Methods for Testing Construction Materials, 
which met at Munich in 1884, Dresden in 1886, Berlin in 1890, and 
at Vienna in 1893. The 1893 meeting was composed of delegates from 
Germany, Austria-Hungary, Switzerland, Russia, France, America, 
N'orway, Holland, Italy, and Spain. {See Appendix 5.) The classifi- 
cation and definitions adopted by this international convention are 
in very close accord with those of all other recognized authorities so 
far as known to the Board. As regards Portland cement itself, these 
definitions have been made more rigid and definite by special resolu- 
tions and agreements of the Association of German Portland Cement 
Manufacturers and the London (England) Chamber of Commerce, 
Cement Trade Section. 

Some of the authoritative definitions of Portland cement and puz- 
zolana cement which the Board has found are as follow^s : 

a. The resolutions of the international conventions held at Munich, 
Dresden, Berlin, and Yienna, for the unification of methods for test- 
ing constructingmaterials, state: 

Portland cements are products obtained from the calcination, up to the verge 
of vitrification, of natural marl or of artificial mixtures of substances contain- 
ing clay and lime. They are reduced to powder by grinding and contain at 
least 1.7 parts, by weight, of lime for 1 part of the material which gives to the 
lime its hydraulic property. To regulate certain properties of technical impor- 
tance, there may be added foreign material up to 2 per cent of the weight with- 
out this addition necessitating any change of name. 

Hydraulic admixtures are natural or artificial materials which generally do 
not harden under water when alone, but only when mixed with caustic limes. 
Such are pozzuolana, santorin earth, trass obtained from certain volcanic tufa, 
furnace slag, burnt clay, etc. 

Pozzuolana cements- are products obtained by intimately mixing powdered 
hydrates of lime with hydraulic mixtures, ground to the fineness of dust. 

h. The Engineering Record of July 9, 1898, page 118, contains 
the following : 

In the French specifications of the Fonts et Chaussees Portland cement is 
defined to be " the product of the grinding of clinkered rock obtained by the 
burning to a point of softening of an intimate mixture of carbonate of lime and 
argillaceous matter, rigorously combined and chemically and physically homo- 
geneous in all its parts." 



15 

By the standard tests accepted by the German Government in a decree of the 
Minister of Public Works dated July 28, 1887, Portland cement is a material 
resulting from the calcination, carried to the point of incipient fusion, of an 
intimate mixture of lime and argillaceous substances as its essential components ; 
such calcination being followed by the grinding of the product to the fineness of 
flour. 

In Switzerland, Portland cements are described to be the product obtained by 
the burning to the point of vitrification of hydraulic lime^stones, or of mixtures 
of argillaceous and calcareous materials, which are subsequently ground and 
reduced to fine powder. Portland cement in addition must contain, a minimum 
of 1.7 parts lime to the unity of hydraulic materials. 

In Austria, in the specifications of the Austrian Engineers and Architects' As- 
sociation, 1890, Portland cement is defined to be " compounds of natural marls or 
artificial mixtures of clay and lime-bearing materials which are burned to vitri- 
fication and are subsequently ground to great fineness, and in which the cal- 
careous material shall at least be 1.7 to the unity of the argillaceous." 

In Russia, the Minister of Roads and Railways defines Portland cement to be 
"a product made out of natural marls or artificial mixtures of materials in which 
clay and carbonate of lime are contained, and which materials are subsequently 
burned to clinker and are thereafter ground to the fineness of flour." 

c. The definition adopted by the Association of German Portland 

Cement Manufacturers, as stated by Jameson, is : 

Portland cement is a product formed by cintering^>' together materials con- 
taining only clay and lime, and finely pulverizing. It is allowable to add not 
more than 3 per cent of plaster of paris, or of some similar substance, for the pur- 
pose of rendering the setting of the cement slower. Beyond this, all additions 
or substitutions are to be regarded as adulterations. 

d. On February 1, 1898, the Cement Trade Section of the London 
Chamber of Commerce adopted the following resolution : 

That Portland cement be defined as a mixture of two or more suitable materials 
intimately and artificially mixed in the requisite proportions, and afterwards 
properly calcined and ground, to which nothing has been added during or after 
calcination, excepting that an addition not exceeding 3 per cent of gypsum is 
permissible for the purpose of regulating the setting. 

That if any material whatever, excepting 3 per cent of gypsum for the j)urpose 
of regulating the setting, be added to the Portland-cement clinker during or after 
calcination, the article so i)roduced shall not be sold as Portland cement, but 
under some other distinctive name. 

e. In "Ciments et Chaux Ilydrauliques," by Candlot, published 
in 18*Jl, is given tlio following extract from general remarks of jNI. 
Telmajer on the subject of slag cements: 

Puzzuolana cements are products obtained by the intimate mixture of slakod 
lime, powdered, with finely ground hydraulic rock. * * '^ Tliis kind of 
cement ought to be designated according to the name of the base used in making 
it — that is, slag cement, trass cement, etc. 

/. In "A Ti'catise on AFasoiiry Construction/' by liaUer, ninth 

edition, 1899, appear tlie following: 



*Cinterinj? is boatiiiK to the tomponituro of incipient fusion. 



IC 

Portland. — Portland cement is produced by calcining a niixtare containing 
fi"om 75 to SO per cent of carbonate of lime and 20 to "23 per cent of clay, at sncli 
a liigb temperature that the silica and alumina of the clay combines Tvith the 
lime of the limestone. ^ ^ ^ 

To secure a complete chemical combination of the clay and the liine, it is nec- 
essary that the raw materials shall be reduced to a powder and be thoroughly 
mixed before bui-ning, and also necessary that the calcination shall take place at 
a high temperature. Those are the distinguishing characteristics of Portland 
cement. 

P?/z^?/oZa r<o. — Puzzuolana is a term applied to a combination of silica and 
alumina which, when mixed with common lime and made into mortar, has the 
property of hardening under water. There are several classes of materials pos- 
sessing this property. 

Slag cejnent. — Slag cement is by far the most important of the puzzuolana 
cements. It is the product obtained by mixing jDowdered slaked lime and finely 
pulverized blast-furnace slag. ^ ^ ^ Probably most of the so-called puzzuo- 
lana cements are slag cements. 

g. In -'Hydraulic Cement," by Spalding, pulDlished in 1S98, 
appear the following : 

The term Portland cement is commonly used to designate hydraulic cement 
formed by burning to the point of vitrifaction a mixture of limestone and clay in 
proper proportions, and reducing the resulting mass to powder by grinding. * - ^ 

Slag cement or, as a more general term, puzzolaiiu cement, is the product ob- 
tained by an intimate mixture of slaked lime with finely pulverized piizzolanic 
material, commonly blast-furnace slag. In this material the hydraulic ingi-edi- 
ents are not burned with the lime, but are present in the cement in a mechanical 
m.ixture only. 

h. In -'Inspection of the Materials and Workmanship Employed 
in Construction.'' by Byrne, j)ublished in 1899, appear the following: 

Portland cement is produced by btuTiing. with a heat of sufficient intensity and 
dui-ation to induce incipient vitrification, certain argillaceous hmestones, or cal- 
careous clays, or an artificial mixture of carbonate of lime and clay, and then 
reducing the biUTit material to powder by grinding. 

Slag cements are those f onned by an admixture of slaked lime with ground 
blast-furnace slag. 

From the above definitions it will he seen that a cement, in order 
to be classified as a Portland cement, must, according to all authori- 
ties, be calcined after the mixture of its argillaceous and calcareous 
constituents; and whenever such calcination, subsequent to such 
mixture, is omitted the product is classed either generically as a 
puzzolana cement, mixed cement, etc.. or specifically, according to 
its hydraulic base, as a slag cement, trass cement, etc. 

In the manufacture of hydraulic cement, authorities agree that 
the method of manufacture is of the utmost importance in determin- 
ing the quality and class of the final product, and that a mere chem- 
ical analysis of the final i)roduct does not determine the properties 
possessed by the resulting cement. Spalding especially calls atten- 



17 

tion to the fact that a Portland cement may be made from pulverized 
burnt argillaceous and calcareous materials mixed with powdered 
slaked lime, provided that the mixture be properly calcined after- 
wards. In other words, it is possible to make a Portland cement 
from slag and lime, but not by the method of mechanical mixture 
without subsequent calcination, as in the present practice of the 
Illinois Steel Company. An examination of the advertising pam- 
phlets of this company, as furnished by it to the Board, fails to show 
the omission of the subsequent calcination absolutely necessary to 
properly entitle its product to classification as a Portland cement, 
and necessary to give such product all the characteristic qualities of 
a Portland. It is quite possible that some military engineers as well 
as many civilian engineers may not have had their attention called 
to this important point in the method of manufacture of this partic- 
ular cement, and have been using it under an erroneous impression 
that its trade name is correct as to classification. 

All authorities, especially the International Convention and the 
Austrian Engineers and Architects' Association, agree that the pro- 
portions of argillaceous and calcareous matters in the calcined product 
must be within certain narrow limits, or else the product will not 
have to the highest degree the characteristics of a Portland cement. 
The limits adopted by them preclude the admission of the Illinois 
Steel Company's cement to the class of Portlands. 

The International Convention, the Association of German Port- 
land Cement Manufacturers, and the London Chamber of Commerce 
all permit not to exceed 2 per cent of additions or substitutions after 
calcination for specific technical purposes. Should these additions 
or substitutions exceed 2 per cent, they demand that the product 
should be sold under other names than Portland cement. Such ruling, 
irrespective of any chemical analysis of the resulting product, would 
not permit the addition after calcination of such a large percentage 
of slaked lime as is used by the Illinois Steel Company'- in the manu- 
facture of its slag cement, if the name of Portland is to be preserved. 

Comparing the qualities of finished products in various cements, 
apparently much alike in appearance or chemical analysis, the ]>oai'd 
is of the opinion that the technical classification above explained has 
the very best of reasons for its adoption and continuance. 

As a final result of its investigation into, the classification of 
hydraulic cements, the Board considers the following definitions as 
almost universally rei^resenting the products defined and nn'oni- 
mends their adoption by the Department: 

Portland ceynents iive in'odwais obtained from the heating or cal- 
cining \i\) to incipient fusion, of intimate^ niixturc^s, (Mther natural 



18 

or artificial, of argillaceous with calcareous substances ; the calcined 
product to contain at least 1.7 times as much of lime, hj weight, as 
of the materials which give the lime its hydraulic properties, and to 
be finely pulverized after said calcination, and thereafter additions 
or substitutions for the purpose only of regulating certain j)roperties 
of technical importance to be allowable to not exceeding 2 per cent 
of the calcined product ; otherwise additions and substitutions after 
calcination are adulterations, necessitating a change of name. 

Puzzolana cements are products obtained b}' intimatelj" and me- 
chanically mixing, without subsequent calcination, powdered hydrates 
of lime with natural or artificial materials which generally do not 
harden under water when alone but do so when mixed with hj'drates 
of lime (such materials being i3uzzolana, santorin earth, trass 
obtained from volcanic tufa, furnace slag, burnt clay, etc.), the 
mixed product being ground to extreme fineness. 

CLASSIFICATION OF ILLINOIS STEEL COMPANY'S CEMENT. 

Under the above definitions, the Board is constrained to state that 
the Illinois Steel Company's cement as at present manufactured 
should be classified under the generic name of puzzolana cement 
and under the specific name of slag cement, and that it can not be 
classified as a high grade American Portland cement nor even as a 
Portland of any grade. The board holds to this classification all the 
more firmly as it finds that the Illinois Steel Company's cement, 
while showing great uniformity and high grade, yet shows the char- 
acteristic qualities of a slag puzzolana cement and not those of a 
Portland cement. 

The differences between these two classes are not those of mere 
definition alone. These differences are numerous and essential, and 
exist in the methods of manufacture of the cements, in the propor- 
tions of their constituents, in their chemical com^Dosition, in their 
physical nature, and in their behavior under varying conditions of 
use and exposure. 

In the letter of Mr. Charles Mac Yeagh, counsel for the Illinois 
and Federal Steel Companies, to the Honorable the Secretary of AYar, 
under date of February 15, 1900, which letter was referred to the 
board by sixth indorsement above quoted, the statement is made "that 
Steel Portland cement is a high-grade American Portland cement, 
so recognized and considered by the trade." In view of this letter 
having apparently been the immediate cause for the convening of 
the Board, this statement can not be allowed to pass without special 
comment. 

The Cement Trade Section of the London Chamber of Commerce 
has specially protested against similarly made slag cements being 



19 

sold under the name of Portland {see Appendix 6, herewith) ; the 
German manufacturers of Portland cements have put an end to such 
practices in Germany ; the French Cori^s des Ponts et Chaussees are 
reported to have refused to admit sla^ cement in their works up to at 
least 1897 {see Appendix 20, herewith) ; at least three of the largest 
and best known Portland cement manufacturers in America have 
XJrotested vigoroi^sly against the sale of slag cements as Portlands in 
the United States ; and this Board believes that every manufacturer 
of Portland cements and the majority of well-informed engineers in 
this country, as in Europe, will support such protests. 

In the letter of Mr. Jasper Whiting, manager of the cement de- 
partment of the Illinois Steel Company, under date of December, 
1899, to Major Adams {see Inclosure 2 of Appendix 2, herewith), 
another statement is made with reference to the Illinois Steel Com- 
pany's cement, as follows: 

That the Government also considers this cement not only equal to Portland 
but a Portland, considering the word in its generic sense, is proved by the fol- 
lowing extract taken from specifications of one of the most important federal 
structures now being erected : 

"All cement used in setting granite or in work in contact with the granite work 
will be a Portland nonstaining cement equal to the La Farge or Meier. * * * 
Cement to be acceptable must pass the following tests, etc." 

It is evident, therefore, from these two examples that the United States Govern- 
ment through its representatives as well as prominent hydraulic material experts 
considered the words ' ' Portland and Puzzolan " as related to cements interchange- 
able, both denoting a hydraulic material, capable of fulfilling certain stated specifi- 
cations. 

In this letter Mr. Whiting's argument is based upon the supposi- 
tion that the Meier cement is a puzzolana and that the La Farge 
cement is a Portland. While the Meier cement is a puzzolana, the 
La Farge cement is a patented cement differing from a Portland in 
possessing nonstaining qualities similar to those of the Meier. 

It is evident to the Board from the pliraseology of the specilications 
referred to that the object of these specifications was to secure, if 
possible, in a Portland cement the si)ecial nonstaining ([ualities of 
tlio two peculiar cements named and not in anj' way to classify either 
of these cements as a Portland. 

Paragrapli 55 of the speci(i(iatioiis of February Id, 18!)8, for tlie 
construction of tlie Phiquemine lock, requires that tlie cement used 
in tlj(i woi'k must be "a high-,iira(U^ American Portland," and also 
requinjs that it must luHill certain tesls tiiereinal'ter named. 

Any liigh-grade American Porthmd cement will easily fuHlU llu^se 
specified requirements. The object of the special tests was evideni ly 
not to secure a cement wliicii would test especially high, but to secure 



20 

a sound and uniform cement of the class specially designated. The 
essence of the specifications, therefore, lies in the words " high-grade 
American Portland," and these specifications can not be interpreted 
to mean that any hydraulic cement not a high-grade American Port- 
land should be accepted merely because it may have passed the pre- 
scribed test. 

The "Steel Portland Cement" therefore should not be accepted 
as a high-grade American Portland within the meaning of the speci- 
fications of February 16, 1898, for the construction of the Plaquemine 
lock. 

USE OF ILLINOIS STEEL COMPANY'S CEMENT AT PLAQUEMINE, LA. 

Regarding the propriety of the use of the Illinois Steel Company's 
cement upon important engineering structures, the Board does not 
feel called upon to go outside of its application to the Plaquemine 
lock. 

This cement is a puzzolana slag cement of first-class quality and 
of exceptional purity and uniformity. Puzzolana cements possess 
many admirable qualities which make them specially useful in cer- 
tain cases, and the conditions most favorable to such uses have not 
only been briefly stated above, but are further given much more in 
detail in the many appendixes hereto attached, especially those of 
Candlot (including his quotations from Tetmajer) and of Mahiels. 
Anyone desiring fuller information is advised to consult the original 
text-books and periodicals from which these extracts and other appen- 
dixes have been taken, as w6ll as other authorities on the subject. 

The present condition of the work at Plaquemine lock has been 
briefly described above and its condition is known to your ofiice 
through the periodical reports which have been made to you from 
time to time during the past year by its ofiicer in charge. 

Under the existing specifications the "Steel Portland Cement," 
herein shown to be not a Portland, is now excluded from use in the 
masonry of this lock. Irrespective of such specifications, it is not 
yet proven to be a proper material for this work. The concrete 
already laid seems of good quality and most probably will prove tdji 
be sufficient for the purpose for which it is intended. Un-der existing 
circumstances, the removal of this concrete is not now considered i 
necessary, especially as it will be subjected to moist conditions favor- 
able to the success of slag cement concretes. 

Although the facing already in place is soft, yet it is below the 
level of the lower pool so that it is unlikely to be abraded by fioating 
bodies, and the removal of this facing and its raplacement by harder 
materials is not now recommended. 



21 

The Board does not know of any failure as yet of the Illinois Steel 
Company's cement concrete where used in massive structures, but 
the use of any unproved cement in the Plaquemine lock seems too 
venturesome to be recommended for a work of such magnitude and 
cost. In this connection, it is to be especially borne in mind that 
European Portland cements have been manufactured and used with 
excellent success for over fifty years ; that American Portlands have 
also been manufactured and used with excellent success for about 
twenty-five years, while European slag cements have been made for 
about thirty j^ears with but poor success and American slag cements 
have been practically unknown until within about five years. Under 
such circumstances the American slag cements, of which the Illinois 
Steel Company's cement is apparently the best up to date, have not 
yet had time to show their ability to stand indefinitely without dis- 
integration or deterioration. 

CONCLUSION. 

In conclusion the Board repeats that the cement manufactured 
and sold hy the Illinois Steel Company under the name of "Steel 
Portland Cement" should be classified under the generic name of 
puzzolana cemeiitTunder the specific name of slag cement and can 
not be classified as a Portland cement. 

The "Steel Portland Cement" therefore should not be accepted as 
a high-grade American Portland within the meaning of the specifica- 
tions of February IG, 1808, for the construction of the Plaquemine 
lock, and irrespective of the specifications, its use in such lock seems 
too venturesome to be recommended for a work of such magnitude 
and cost. 



Respectfully submitted. 



Brig. Gen. John M. Wilson, 

Chief of Engineers, U. S. A. 



W. L. Marshall, 
Major, Corps of Engineers. 
Wm. H. Bixby, 

Major, Corps of Engineers. 

C. S. RiCHE, 

Captain, Corps of Engineers. 



LIST OF APPENDIXES. 



Appendix 1. 



Appendix 2. 



Appendix 3. 
Appendix 4. 

Appendix 5. 



Appendix 6. 

Appendix 7. 
Appendix 8. 
Appendix 9, 

Appendix 10. 
Appendix 11. 

Appendix 12. 
Appendix 13. 
Appendix 14. 
Appendix 15. 



Letter of E. J. Buffington to Maj. W. L. Marshall, March 19, 1900. 
Inclosure 1. Letter of C. H. Foote to Jasper Whiting, March 

17, 1900. 
Inclosure 2. Letter of Jasper Whiting to E. J. Buffington^ 
March 16, 1900. 

Exhibit A. Briquette (not forwarded) . 
Exhibit C. Slag specifications. 
Exhibit D. Analyses of ores and limestones. 
Exhibit E. Analyses of slag. 
Exhibit F. Analysis of " Steel Portland Cement." 
Exhibit G. Advertising Pamphlet * (forwarded sepa- 
rately). 
Exhibit B. Tests of "Steel Portland Cement." 
Inclosure 3. Tests of "Steel Portland Cement." 
Letter of E. J. Buffington to Maj. W. L. Marshall, March 21, 1900. 
Inclosure 1. Patent specifications. 

Inclosure 2. Letter of Jasper Whiting to Maj. H. M. 
Adams, December, 1899. 
Letter of E. J. Buffington to the Board, March 24, 1900. 
Tests of Illinois Steel Company's cement made by the United 

States at Plaquemine, La. 
Extracts from resolutions of International Convention held at 
Munich, Dresden, Berlin, and Vienna for the unification of 
methods for testing construction materials — Bauschinger. 
Cement Admixtures, Cement Trade Section, London Chamber of 

Commerce. 
Extracts from " Ciments et Chaux Hydrauliques, " Candlot, 1891. 
Extracts from "Le Beton et Son Emploi," Mahiels, 1893. 
Extracts from ' ' Fabrication et Controle des Chaux Hydrauliques 

et des Ciments," Bonnami, 1888. 
Extracts from "A Manual of Lime and Cement," Heath, 1893. 
Extracts from "Inspection of the Materials and Workmanship 

Employed in Construction," Byrne, 1899. 
Extracts from ' ' A Treatise on Masonry Construction," Baker, 1899. 
Extracts from "Hydraulic Cement," Spalding, 1898. 
Extracts from "Portland Cement," Jameson, 1898. 
Extract from proceedings of Institution of Civil Engineers, Eng- 
land; abstract of "The Manufacture of Slag Cement," C^ros- 
claude, 1889. 

* Not printed. 
(22) , 



23 



Appendix 16. Extract from proceedings of Institution of Civil Engineers, Eng- 
land; extract from "The Manufacture and Properties of Slag 
Cement," Redgrave, 1891, 

Appendix 17. Extract from proceedings of Institution of Civil Engineers, Eng- 
land; abstract of "Slag Cement Experiments," Mahon, 1894. 

Appendix 18. Extract from United States Consular Reports; " Slag Cements in 
Germany, Frankfort," Mason, 1895. 

Appendix 19. Extract from proceedings of Institution of Civil Engineers, Eng- 
land ; abstract of ' ' History of Slag Cement in Regard to Expan- 
sion According to Austrian Rules," Berger, 1897. 

Appendix 20. Extract from Engineering and Mining Journal; "Notes on the 
Manufacture and Properties of Blast-Furnace Slag Cement," 
Elbers, 1897. 

Appendix 21. Extract from pamphlet, " The Utilization of Blast-Furnace Slag 
and its Possibilities," Elbers, 1898. 

Appendix 22. Extract from transactions of American Society of Civil Engineers, 
"Slag Cement," discussion, Lesley. 

Appendix 28. Extract from Engineering News; "Some Results of a Test of a 
Hydraulic Cement Containing a Large Percentage of Sulphides," 
Russell, 1898. 

Appendix 24. Extract from Engineering News; "Hydraulic Cements Contain- 
ing a Large Percentage of Sulphides," Li^dngston, 1898. 

Appendix 25. Extract from Engineering Record ; extract from ' ' Slag Portland 
Cement," anonymous, 1899. 

Appendix 26. Extract from Engineering Record ; "The Distinction between Slag 
and Portland Cements," anonymous, 1898. 



APPEXDIXES. 



Appendix 1. 
Letter of president of Illinois Steel Company to Major Marshall. 

Office of President, 



5 



Illinois Steel Company, 

"The Rookery," 
Chicago, March 19, 1900. 
Dear Sir: Referring to your request that the Board of Govern- 
ment Engineers, appointed to investigate with reference to the manu- 
facture and quality of our Steel Portland cement, be furnished in 
writing a chemical analysis of the cement and a description of the 
process of its manufacture, I herewith append the same in the form 
of a written report to me by Mr. Jasper Whiting, manager of our 
cement department; also a written statement from Mr. C. H. Foote, 
first vice-president, setting forth the care with which slag is selected 
for cement manufacture and our facilities for obtaining the same. 
Respectfully submitting these reports, I remain. 

Yours, very truly, 

E. J. Buffington, 

President. 
Maj. W. L. Marshall, 

Corps of Engineers, U. S. A., 

Chicago, 111. 



[Inclosure 1.] 
Letter of the first vice-president of the Illinois Steel Company to the manager of 

the cement department. 

Office of First Vice-President, 

Illinois Steel Company, 

"The Rookery," 
Chicago, March 17, 1900. 

Dear Sir: Regarding the manufacture of slag for Steel Portland cement, I 
beg to say that I have been connected with the iron business since 1866 ; eighteen 
years of this time as superintendent of blast furnaces in the State of ISTew York, a 
portion of one year in like capacity in the State of Pennsylvania, eleven years as 
superintendent and manager of the blast furnaces of this company, and four years 
as first vice-president of this company. For the past nine years I have purchased 
the iron ores used by this company, averaging but little, if any, less than 2, 000, 000 

(24) 



25 

tons per year. I am also familiar with the ores and blast-furnace practice both 
of this country and Europe, and unhesitatingly say, without fear of contradiction, 
that the Lake Superior ores which we use exclusively when making slag for Steel 
Portland cement, for uniformity and purity, surpass those produced in any other 
section, not only of this country, but the world. 

The variation in ore from the same mine rarely, if ever, exceeds in combined 
contents of silica, alumina, lime, and magnesia more than 2 per cent in the 
various cargoes received during the season, and sometimes covering as much 
as 500, 000-ton shipments from the same mine. None of the Lake Superior 
ores which we purchase will show by analysis to exceed .09 in sulphur. We 
purchase in large blocks from the same mine, seldom less than 20,000 tons, 
and from this up to 1,000,000 tons, as note the case of Fayal. In making slag for 
the Steel Portland cement, we select from the various ores purchased those which 
are the most uniform and are low in magnesia, and besides this great care is 
taken in the selection of limestone and coke. As you are aware, limestone for 
the manufacture of the slag used in your Steel Portland cement has been brought 
from the southern portion of Indiana, more than 300 miles from Chicago, at a 
cost exceeding 35 cents per ton over that of limestone which was suitable for 
flux, but not suitable for the manufacture of cement. Only recently, however, 
a large investment was made by this company in a limestone quarry near Fair- 
mount, of this state, after making exhaustive tests and chemical analyses, which 
show the stone to be under .75 percent in magnesia, and not less than 53 per cent 
of lime in any instance. The limestone from this new quarry will not cost any 
more than the limestone heretofore used by this company in its furnaces. At 
the same time the limestone is exceedingly uniform in composition and admi- 
rably adapted for the production of slag for cement purjDOses. 

I know that such conditions for producing a uniform slag do not exist in any 
section that is not favored with the ores from Lake Superior and believe that I 
am safe in saying that our slag from the blast furnace will not vary as much in 
chemical composition as the marls and rock used in the very highest gi'ades of 
cement. 

Should you wish further evidence of the purity of these ores, I shall be pleased 
to submit it to you in the form of our cargo analyses of these ores as received 
■during the year, and also the average yearly analyses of Lake Superior ores from 
the .same mines for the past seven or eight years. 
Yours, truly, 

Chas. H. Foote, 

First Vice-President. 
Mr, Jasper Whiting, 

Manager, Cement Department. 



[Inclosure 2.1 
Letter of the manager of the cement department to the president of the JUiitois 

Steel Conrpamj. 

Ciiicuio, March 10, 19(>fK 

Dear Sill: In accordance with your request, I beg to submit the following 
brief description of our method of manufacturing Steel Poitland coniout :it 
North Works. 

The XH'ocess is covered by United States patent No. 544700. dated August 20. 
1895, issued to Jasper Whiting but now controlled by the Illinois Stool Company. 
No other cement is manufactured by this proco.ss except at the works of the 
Brier Hill Iron and Coal Company, Youngstown, Ohio, The cement manufiu*- 



26 

tnred by the Brier Hill Iron and Coal Company is manufactured under a license- 
held from the Illinois Steel Company and its plant was designed and put in oper- 
ation by me with especial reference to our process. 

The patent above referred to was the result of a long series of experiments 
conducted by me at the North Works of the Illinois Steel Company covering a 
period of nearly two years. The first successful results of these experiments 
were achieved in August, 1894, when briquettes were made of the cement and 
the material tested in other ways and pronounced satisfactory by competent 
authorities. One of these original briquettes is still in our i^ossession and is 
apparently in excellent condition. (Exhibit A.*) 

Soon after the above patent was obtained several car loads of slag, together 
with other necessary ingredients, were shipped to New York, where machinery 
was found suitable for manufacturing the cement. The product was tested by 
various authorities including the Croton Aqueduct Commission, report of whose 
test is hereto attached. (Exhibit B.) 

The cement manufactured in New York was shipped back to Chicago and used 
in the construction of a small plant erected for the purpose of manufacturing 
the cement, which plant was put in operation about March, 1896. 

The machinery installed at that time is still in operation at North Works, the 
present plant at this point being merely an enlargement of the original plant. 
The foundations put in with this cement are accessible for examination at any 
time. 

The process of manufacturing Steel Portland cement may briefly be stated as 
follows : 

Slag of the proper composition is made to flow from the furnace in which it is 
produced through an open trough to the chilling tank, where a large stream of 
cold water under high pressure is directed against it at right angles to its flow. 
Contact between the slag and cold water not only causes the slag to break up and 
disintegrate, but eliminates about one-third of its sulphur and changes it chem- 
ically in such a way as to render it suitable for the manufacture of cement. 

This chilling operation is a highly important factor in the process, and great 
care is taken to control the stream of slag and the flow of water in such a way 
as to make the chilling complete and uniform. After each lot of slag is chilled, 
a sample of it is taken and examined both chemically and physically in the com- 
pany's laboratory. If the results of this examination are satisfactorj^, the slag 
is conveyed by means of cars to the cement plant, where another sample of it is 
taken and mixed with a definite proportion of prepared lime and the whole ground 
in a miniature mill where actual cement is produced. This trial cement is then 
submitted to physical and chemical tests to prove beyond a doubt that the raw 
materials and mixtures are correct. This test, reproducing as it does the actual 
conditions of manufacture, eliminates all experimental error and gives an accu- 
rate knowledge of what the finished cement will be. It is a precaution not taken, 
so far as we know, by the manufacturers of any other cement. 

The preliminary examination of the raw materials being complete, the slag is 
then passed through a dryer of special design and conveyed by an elevator into 
bins located over grinding mills of the Griffin type, which are used for prelimi- 
nary pulverization. It is then conveyed by means of another elevator into bins 
over grinding machines of the tube-mill type, where it is mixed with the proper 
proportions of prepared lime, as previously determined, and the two materials 
gi'ound and intimately mixed together in the above-mentioned tube mills. The 
resulting powder, which is so fine that not over 4 per cent is left on a 200-mesh 

* Omitted. 



27 

sieve, is then conveyed by means of screws and elevators into large bins, from 
which it is drawn and packed into barrels and bags for the market. 

An important element in the manufacture of cement is the prepared lime. This 
lime, which is obtained from the calcination of Marblehead limestone or Bedford 
stone (as pure as exist in the country), is unloaded into bins beneath which are 
placed two screens of different mesh, the coarse at the top. A quantity of lime 
is drawn on the top screen, where it is slaked by means of the addition of water 
containing in solution a small percentage of caustic soda. As the material is 
slaked it falls through the coarse screen onto the finer screen, after passing 
which it falls into a conveyor and is conveyed to a rotary dryer. It would be 
perfectly possible to slake this lime and incorporate with it the desired quantity 
of caustic soda without any additional heat, but by so doing there is great danger 
of having present particles of unslaked lime, which would render the resulting 
cement unfit for use. The wet and perfectly slaked lime therefore is conveyed 
into the aforementioned dryer, and the final slaking done by the application of 
heat, so that every particle of lime is thoroughly slaked and the soda incorporated 
with it in the most perfect manner. The resulting prepared lime is then conveyed 
by means of elevators and screws into hoppers over the tube mills, where it is 
mixed with the ground slag in known but varying proportions. 

Continual tests are made of the resulting products and every car that is shipped 
out is accompanied by a signed statement giving complete tests on contents. 

This is a description in brief of the method of making Steel Portland cement. 
It does not include, however, the main feature of the process, which consists of 
taking the necessary steps to obtain a slag of the correct composition. Good 
cement can not be made from slag of improper composition any more than it can 
from limestone and clay of improper comiDosition, and to the inability to appre- 
ciate this fact may be attributed a large iDroportion of the failures of the manu- 
facturers of foreign slag cements. 

The Illinois Steel Company owns and operates seventeen blast furnaces, only 
two of which produce slag for the manufacture of cement. The ores that are 
smelted in these furnaces are the purest and most regular in the world. They 
vary somewhat in composition, however, some ores containing higher percent- 
ages of silica and alumina than others, some containing considerable magnesia 
and others but little, and some containing a considerable percentage of phos- 
phorus while others have practically none. It is entirely i)ossible, therefore, for 
the Illinois Steel Company to so choose their ores as to use in the furnaces making 
slag for cement purposes only those which will give a slag of the proper compo- 
sition, and this choosing of the ores involves no extra expense to the Illinois 
Steel Comi)any. It is the same way with the limestone used in fluxing these 
ores. Stone from our different (luarries varies in its composition from practically 
pure dolomite to a very pure calcite. Ordinarily in making iron the presence of 
a reasonable amount of magnesia in the flux is not considered harmful, but in 
the furnaces making slag for cement the greatest care is taken to insure the use 
of only the jmrest calcite. It will be seen, therefore, that without any additional 
expense to the Illinois Steel Company, other than the cost of close supervision, it 
is possible for it to obtain a slag of the desired composition, and such is the case. 

In order to have a clear understanding as to the proi)er composition o\' slag 
used for manufacturing cement, the cement department furnishes to the blast 
furnace department a sot of specifications covering this material. If any slag 
is made the composition of which falls without these specifications it is rejected 
at the furnaces and is not shipped to the cement plant. A coi)y of these specifi- 
cations is attached. (Exhibit C. ) 



28 

I also attach analyses of ores and limestone used in furnaces making slag for 
the cement works and other analyses of the same materials used in furnaces in 
which no attention is paid to the availability of slag for cement purposes. On 
the same sheet are shown analyses of the resulting slag from both furnaces. 
(Exhibit D. ) 

The iron in both cases is of the same composition. 

I also attach a large number of analyses of slag used in the manufacture of 
cement, to show the uniformity of composition of this material. The figures 
are taken from our records and may be verified at any time. (Exhibit E. ) 

I also send you two analyses, one made by Dickman & Mackenzie, of Chicago, 
and one by Professor Wilkinson, of Tulane University of Louisiana, at New 
Orleans, and also several analyses of our cement made in our own laboratories. 
(Exhibit F. ) 

I also attach pamphlet recently issued in the interests of Steel Portland cement, 
in which are contained copies of a number of chemical and physical tests made 
on this material by independent competent engineers. (Exhibit G.*) 

I also attach a letter received from Mr. C. H. Foote, our first vice-president, 

in which he clearly states the character of the ores and limestones used in the 

furnaces of the company and draws particular attention to the care which is 

taken to produce a slag especially suitable for cement-making purposes. This 

letter speaks for itself. 

Yours, respectfully, 

Jasper Whiting, 

Manager, Cement Department. 
E. J. BuFFiXGTOX, Esq., 

President Illinois Steel Company, 1027 The Rookery, City. 



[Exhibit C] 

Specifications for slag used in the manufacture of Steel , Portland cement. 

Slag must analyze within the following limits : 

Per cent. 

Silica plus alumina, not over 49 

Alumina 13 to 16 

Magnesia, under 4 

Slag must be made in a hot furnace and must be of a light gray color. 

Slag must be thoroughly disintegrated by the action of a large stream of cold 
water directed against it with considerable force. This contact should be made 
as near the furnace as is possible. 



[Exhibit D.] 

Analyses of ores and limestones used in furnaces making slag for the cement 
works and for other purposes and analyses of the resulting slag from these 
furnaces. 

SLAG. 



Silica. 



Iron 

Alu- I Lime, 
mina. i 



Magne- 
sia. 



Mn.ox. Sul, 



Iron. 



Cement slag ' 34. 70 

Other slag i ) 30' 00 



14.76 ! 46.20 
14.00 i 34.70 
17.00 ! 



L92 
16.90 



.46 

,30 
,40 



1.56 
1.70 



* Not printed. 



29 

LIMESTONE. 



For cement 

Not for cement 



1,76 
( 2.75 
'/ 3.68 



1.60 52.27 .65 

2.46 \ 29.^2 20.41 
2.54 40.38 10.61) 



ORES. 



For cement 

Not for cement 
Gray ore 



( 2.44 
■I 4.78 
1 2.91 
( 5.88 
1 4.97 
20.18 


.79 
1.15 
1.37 
3.80 
1.38 
1.80 


.51 

.31 

.40 

1.01 

1.72 

2.95 


.19 
.17 
.14 
.88 
3.63 
3.79 




















1 




' 







56.98 
55.88 
56.66 
61.00 

54.88 
46.47 



[Exhibit E.] 
Analyses of slag used in the manufacture of Steel Portland cement. 



Date. 


Silica. 


^^] Ltae. 


Magne- 
sia. 


November 29 


32.76 
33.00 


18.40 
13.80 












33. 60 


14.40 








33.00 


13.60 








33. 40 


14.70 






November 30 


33.20 
33.80 


13.60 
14.40 












33.40 


14.20 








32.80 


14.10 








31.40 


15. 40 








81.84 


14.20 








32.80 


14.74 








31.70 


14.90 








33.20 


14.96 






December 1 


31.36 
31.36 


15.06 
1.5.00 


49.01 


2 59 








32.40 


15. 14 








32. 80 


14.20 








31.76 


15.10 








32.60 


16.40 








32.84 


14.80 








31.20 


15.20 








30.40 


15.10 








32.i)0 


15.50 








32. 04 


14.90 








32. 90 


14.40 








33. 30 


14.20 








33.34 


14. 70 






December 3 


31.00 
34.00 


14.30 
14.20 












32.10 


14.70 








32.00 


15.30 








31.60 


15. 50 








32. 70 


15.90 








3;?.;?o 


15. 50 








34. 70 


15.60 








34.30 14.76 






December 4 


;3;i.60 14. (K) 
;L». 60 15. 46 


48.11 


2 66 








34. 00 15. 40 








32.00 1 14.90 








32. 90 


16.20 








:W. 8(5 


1.5.36 








34.50 


15.96 







30 

[Exhibit F.J 
Analysis of Steel Portland cement. 



Made by— 



Silica, j ^^J" ! Lime. ^^|g^^- Sul. 



Vol. 



Dickman & Mackenzie, Chicago. Ill 28. 95 11. 94 ; 50. 29 

Prof. Wilkinson, Tulane University i 28. 40 ' 12. 8() 51. 50 

Illinois Steel Co ■; ! 29. UU 12.20 ! 51.28 

Do I 28.60 1^.30 o2.U 

Do 29. 10 12. 30 51. 66 

Do i 28.94, 11.60 51.87 

Do 28.20 11.40 .51.41 

Do 27.80 11.10 .50.96 

Do ! 29.10 12.00 .50.78 

Do .... 29.00 1 11.60 ; 50.36 

Do 29.80 12.30 51.14 

Do .' 29.50' 12.30 51.23 

Do 29.90 13.00 51.19 

Do 28.30 12.30 50.87 

Do 28. 50 12. 20 i 51 . .50 

Do : 29.40 1 12.70 1 51.19 



2.96 I 



2.30 
2.23 
2.23 
1.87 
1.58 
2.:-'3 
2.20 
2.05 
2.34 
2.01 
2.05 
2.48 
2.41 
2.34 



1.37 

1.40 . 

1.40 

1.47 

1.44 

1.23 

1.14 i 

1.18 

1.25 

1.18 

1.37 

1.26 

1.42 

1.48 

1.47 

1.45 I 



3.39 



4.00 
3.60 
3.50 
4.00 
4.50 
5.30 
4.70 
5.50 
2.60 
4.10 
3.00 
3.70 
3.90 
2.80 



Analysis of slag used in the manufacture of Steel Portland cement. 



Silica. 



34.80 
b2.50 
35.40 
33.20 
33.94 
32.40 
31.90 
33.00 
32.90 
33. 60 
3 ). 20 
31.40 
33.50 
31. 80 
32.80 
32.10 
32.50 
32.40 
33.10 
33.40 
31. 70 
30.80 
-31.60 
31.90 
33. 00 
32.90 
32.20 
_31.60 
30.40 
32.30 
30.00 
33.40 
32.70 
30. 60 
32.60 
31.80 
33.00 
34.00 
32.40 
32.00 
31.60 
82.20 
34.10 
35.60 
34.60 
34.40 
31. 80 
34.80 
34.60 
32.90 
33. 80 



Al. i 
Fe. 



Lime. 



13.66 
15.00 
14.80 
14.80 
14.00 
13.60 
14.40 
14.40 
14.00 
13.60 
14.10 
14. 50 
14.30 
14.00 
15.00 
15.00 
14. 50 
15.00 
14.70 
14.40 
15.20 
14.50 
15.80 
14.80 
15.00 
15.20 
14.50 
14.80 
15.10 
14.70 
16.80 
15.00 
14.70 
15.00 
14.50 
14.70 
15.00 
13.80 
14.40 
15.60 
15.10 
15.00 
14.90 
13.30 
13. 20 
13. 90 
14.80 
14. 60 
14.10 
14. 60 
14.30 



Magne- 
sia. 



Silica. 



^^e* Lime. Magoe- siijea. AL^& ^j^,. Mjgne- 





1 

































1 








, 




1 


50.48 


3. is ! 



33.00 
34.50 
33.60 
31.50 
30.90 
31.50 
32.50 
33. 70 
33.60 
32.40 
31.80 
3:3.50 
32.00 
31. 30 
32.45 
33.10 
31.80 
33.60 
33.70 
32.20 
31.00 
31.30 
31.60 
32.90 
32.10 
32 60 
32.80 
32. 70 
30.00 
31.50 
32.60 
32.40 
32.50 
30.00 
33.00 
32.20 
32.80 
33. 0<) 
32.30 
32.24 
33.30 
32.40 
34.20 
35.10 
32.00 
34. 10 
33.60 
31.60 
33.2(» 
33.10 
31.80 



14. 50 
13.80 
14.40 
14.50 
15.40 
14.90 
14.50 
14.60 
14.70 
14.60 
15.20 
14.90 
17.10 
16.00 
15.09 
15.40 
14.80 
15.10 
16.10 
15.50 
15. 40 
15. 5() 
16.40 
16.40 
15.70 
16.40 
15.80 
16.60 
15.40 
15.10 
14.00 
14.20 
13.50 
14.30 
14.30 
14.30 
15. 20 
13.30 
13.10 
14.10 
13.10 
13.80 
12.86 
12. 90 
13. 30 
13. 20 
13.60 
14.00 
13.50 
12.60 
13.10 



































47.99 


2.65 








































48.14 


2.37 

























































:::::::: 



























































49.98 


3.45 



32.00 
33.00 
32.96 
32.80 
33.40 
31.80 
32.10 
32.50 
32.40 
34.20 
32.60 
34.20 
32.70 
32.50 
34.00 
32.00 
30.60 
30.40 
34.20 
32.20 
33.60 
33.10 
3L70 
29.60 
33.40 
32.50 
33.60 
32.76 
33.00 
33.60 
33.00 
33.40 
33.20 
33. 80 
33.40 
32.80 
31.40 
31.84 
32.80 
31.70 
3:3.20 
31.36 
31.86 
32.40 
32. 80 
31.76 
82. 60 
32.84 
31.20 
30.40 
32.50 



13.80 
13.00 
14.80 
13.90 
13.00 
13.20 
13.40 
13.54 
13.00 
13.30 
13.30 
14.10 
13.00 
13.50 
12.80 
13.86 
14.30 
14.40 
13.60 
13.70 
13.40 
14.30 
13.40 
13.70 
13.14 
13.70 
13.60 
13.40 
13. 80 
14.40 
13.60 
14.70 
13.60 
14.40 
14.20 
14.10 
15.40 
14.20 
14.74 
14.90 
14.96 
15.00 
15.00 
15.14 
14.20 
15.10 
16.40 
14.80 
15.20 
15.10 
15.50 



49.01 



2.59 



31 



Analysis of slag used in the manufacture of Steel Portland cement— Continued. 



Silica. 


Al. & 
Fe. 


Lime. 


Magne- 
sia. 


Silica. 


Al. & 
Fe. 


Lime. |^^f,^«- Silica. 


Al. & 
Fe. 


Lime. Magne- 


82 04 


14.90 
14. 40 
14.20 
14.70 
14.30 
14.20 
14.70 
15. 30 
15.50 
15. 90 
15.50 
15.60 
14.76 
14.00 
15.46 
15. 40 
14.90 
16.20 
15.36 
15.96 
15. 80 
13.10 
15. 40 
15.70 
15.90 
15.50 
14.80 
15. 66 
15.10 
15.26 






33.00 
32.60 
3:3.30 
33. 10 
33.00 
33.60 
32.20 
32.24 
32. 30 
33.20 
31.80 
31.90 
32.20 
31.70 
31.80 
31.10 
31.90 
33.00 
I 31.60 
i 32.00 
32. 80 
i 81.60 
82. 00 
83.00 
34.30 
32.50 
32.50 
i 31. 60 
32.50 
84.00 
84.60 
82.20 
31.80 
33.10 
31.10 
32.90 
! 32.20 
! 32. 40 


15.40 
14.90 
14.70 
15.00 
14. 70 
13.60 
13.20 
14.00 
14.10 
13.80 
14.00 




32.90 
32. 70 
32.20 
33.00 
:32. 80 


14.30 
14. 60 
13. 2U 
15. 10 
16.20 
14.80 
14.80 
14.70 
It. 00 
15. 00 
15.00 
15.04 
14.50 
14.70 
15.00 




82 30 






1 


j 


33 30 






1 




33 34 








. ... 




34 00 








1 




34 00 










33.20 
32. 50 
32. 80 
32. 10 
33. 10 
33.90 
30.60 
32. 60 
1 31.70 
32. 90 
83.50 

32. no 

, 83. 40 
1 33.40 
1 33.00 
1 34. 20 
82.40 
33. 50 
33.10 
33.70 
34.04 
32.90 
83.00 
33. 20 
24. 40 
32.80 
32. 00 
32.80 
32.80 
32.80 
31.60 
32.50 
33.50 






32 10 














32 00 














81 6n 














82 10 












83 30 












84 70 






13. 90 






! 


34 30 


48.11 


3.66 


14.50 
14.40 
14.80 
14.50 
14 12 
13.86 
14. 90 








33 30 








32 60 












84 00 










14.80 
14.80 
14.40 
14.60 
14.70 
14.66 
15.00 
15.50 
15.40 
15.30 
14.50 
14. 60 
14.00 
14.30 
14.80 
14.10 
14.60 
14.20 
14.20 
14.90 
14.50 





32 00 












33 90 










1 


83 86 










1 


34 50 






14.00 
14.80 
14.80 
14.70 
14.20 
14.70 
18.49 
14.60 
15. 60 
13.80 
14.40 
14.10 
14.80 






j 


83 50 












82 86 










1 


82 90 










' 


33 20 












32 00 












32 40 












83. 20 


49.01 


2.81 








81.90 








32.80 












32. 46 












33. 16 


15.20 
14.40 
15.00 












33.60 








"'3.' 29" 




34.10 






14.80 1 49.74 


I 


33. 70 


14. 70 
14.76 
14. 60 
14.96 
15.80 






14.00 
15.08 
14.00 
14.90 
14.30 






34.10 












83. 50 










1 


32. 26 










15. 10 
14.70 






31. 80 










48.58 


3 09 

















[Exhibit B.] 

JReport of tests on Steel Portland cement, August 1, 1896, made by the Croton 
Aqueduct Commission, State of New York. 












© 


















-♦J 




S° 


a 














Propor- 
tion by 
vol- 
ume. 


If 



Final 

setting 

time. 


©■p 

11 





CM 




* Tensile strength in pounds per 


square 


inch. 


Date \t'hen 










P4 

a 












mixed. 




c3 g 
fe© 




H 


E-i 


• 



















































u 


u 
















. 


4J 






4J 

© 


© 




w 


© 


eS 

© 
Q 


© 


«5 

u 

% 




en 
-a 


■M 

a 


a 

CO 


CO 
§ 

a 


b5 

i 


i 


1895. 






























July ;51 


1 





28 


2 


26 


5(5 


03 


149.6 


370.0 


363 


43l{ 


401.4 


511.8 


575. s 


Do 


1 


3 


4U 


1 


•> 


54 


50 




455 4 ' nit:? •» 


008. 8 


713.8 


870 


874.3 













* All figures averages of ten briciuettos. 

Ei>\v. IMkzijkr. 



Division Eitgiiurr. 



32 

[Inclosure 3.] 
Tests of Steel Portland cement. 



No. 



1327 

13:i7 
1327 
1572 
1572 
1572 
1619 
1&49 
1649 
2313 
2313 
2313 
2958 
2958 
2958 
4261 
4261 
5364 
5364 
9151 
9151 
5064 
5064 
1572 
1572 
1572 
1757 
1757 
1757 
4694 
4694 
5805 
5805 
6386 
6386 
784 
784 
9284 
9284 
1020 
1020 
7,354 
7354 
8164 
8164 
1552 
1552 
5252 
5252 
9228 
9228 
8207 
8207 
5413 
5413 
2050 
2050 
2050 
2492 
2492 
2492 
7044 
7044 
7299 
7299 
7962 
9290 
9290 
1907 
1907 
6611 
6611 



Date. 



Pine. 



Set 
tune. 



Propor- 
tion. 



3.0 



Ce- 
ment. 



Sand. 



24 hrs. 7 dys. 1 mo. 3 mo. 6 mo. 1 yr. 2 yrs 3 yrs. 



H. M. 



Apr. 27,1896 

do 

do 

Apr. 11,1896 5.5 

do 

do 

Apr. 15,1896 11.6 i 

do 

do 

Apr. 23. 1896 8. 

do.; 

do 

May 8,1896 3.9 

do 

do... 

May 25.1896 1.7 50 

do.; 

June 11.1896 .4 1 05 

do.. 

Aug. 28,1896 1.2 30 

do I 

Dec. 26,1896 2.5 1 45 l 

do ! 

Apr. 20,1896 5.5 

do 

do 

May 5.1896 4.0 i 

....:do.; 

do ' 

June 5,1896 2.4 1 25 

do 

June 21. 1896 .7 50 

do.. 

Julv 10,1896 .5 1 15 

.....■"do 

Sept. 20. 1896 1.8 40 

do.; 

Oct. 5,1896 l.i 1 10 

do 

Dec. 3,1896 3.5 1 05 

do 

Jan. 6.1897 2.7 2 30 

do.; 

Peb. 7.1897 1.9 1 30 , 

do.; I 

Peb. 16,1897 2.6 1 30 ( 

do 

Peb. 23,1897 1.8 2 05 . 

do 

Mar. 5,1897 1.9 1 55 

do 

Apr. 30,1897 .5 2 05 

do 

Sept. 20,1897 1.2 2 15 

do ■ ; 

Apr. 18,1897 3.0 ; 

do [ I 

do I 

May 10,1897 .74 

do 

do 

Jime24,1897 .7 1 20 

do 

June 29. 1897 .9 1 20 

do 

Julv 6.1897 .8 1 25 

Aug. 20, 1897 1.0 1 50 

do 

June 5,1897 1.7 j 1 35 

do i 

July 24,1897 1.2 1 35 
do 



100 

33 

25 
100 

33 

25 
100 

33 

25 
100 

33 

25 
100 

33 

25 
100 

35 
100 

25 
100 

35 
100 

25 
100 

33 

25 
1(10 

33 

35 
100 

25 
100 

25 
100 

25 
100 

25 
100 

25 
100 

25 
100 

25 
100 

35 
100 

35 
100 

25 
100 

25 
100 

25 
100 

25 
100 

m 

25 
100 

25 
100 

25 
100 

25 
100 

25 
100 

35 



100 
25 



67 
75 i 



67 
75 



67 



67 
75 



67 
75 



75 

"75' 
"75" 

75 

67 



75 



to 
75 



<o 
'75' 
'75 
*75' 

75 
'75' 



67 
75 



75 
'75' 
■75' 



, . . . I 
75 \. 



187 



306 

'sii" 
'288' 

'380' 
"278' 
"3i8' 
'276" 
'345" 
'305' 
"296" 
'260" 
*£62' 
"315" 
"24!" 



221 



282 



315 
'3O6' 
"'56' 
*2i6' 

277* 



315 



220 I 
'266 



394 
195 
383 



317 
'337' 



455 



431 

242 
141 
422 
234 
141 
411 
186 
121 
522 
322 
176 
419 
305 
156 
450 
330 
469 
202 
184 
107 
484 
156 
422 
234 
141 
378 
277 
170 



214 

461 

133 1 

487 i 

192 I 

510 

317 ! 

510 j 

243 I 

384 

228 

473 

165 

406 

221 

576 

156 I 

417 

178 ) 

418 

213 i 

426 

176 

500 

243 

446 

276 

160 

384 

190 

516 

152 

316 

266 

502 ; 

173 
327 

2.50 
525 
342 
626 
220 



520 
383 
211 
437 
327 
217 

528 , 
320 
219 \ 
505 
445 
232 
487 
443 
244 
560 
463 
523 
265 
229 
275 
608 
224 
437 
327 
217 
526 
422 
287 i 
499 ' 
307 
522 ' 
239 ; 
629 ! 
319 j 

"485* ■ 
43S I 
364 

529 i 
393 ' 
602 
304 , 
543 
343 I 
631 ' 
297 
474 
297 
491 
272 
569 
331 
537 
318 
.577 
459 
252 
497 
307 
672 
256 
504 
a56 
527 
314 , 

*3SS" 
543 
411 
785 
315 



609 
513 
241 
533 
452 
291 
603 
426 
271 
637 
520 
320 
547 
.501 
373 
512 
556 
511 
346 
305 
427 
551 
301 
535 
452 
291 
621 
481 
325 
544 
402 
594 
366 
636 
410 
532 
463 
771 
448 
511 
455 
568 
395 
642 
484 
620 
480 
597 
401 
504 
351 
690 
377 
739 
419 
632 
555 
352 
572 
442 
690 
330 
558 
396 
657 
383 
481 
462 
653 
482 
761 
331 



785 
505 
315 
695 
493 
347 
645 
4.58 
320 
719 
592 
374 
649 
569 
435 
575 
571 
609 
396 
404 
491 
699 
391 
695 
493 
347 
702 
551 
347 
588 
434 
600 
382 
609 
490 
616 
463 
803 
428 
621 
441 
601 
382 
577 
527 
771 
416 
782 
479 
709 
489 
743 
488 
644 
436 
702 
571 
423 
601 
489 
707 
404 
595 
440 
622 
380 

'480" 
616 
512 
770 
438 



748 
516 
312 
676 
540 
364 
648 
763 
349 
720 
641 
484 
697 
553 
483 
625 
578 
581 
427 
506 
523 
795 
425 
676 
540 
364 
677 
579 
381 
664 
460 
532 
400 
727 
429 
634 
532 
771 
421 
756 
523 
669 
498 
679 
576 
761 
501 
740 
545 
730 
469 
723 
540 
843 
482 
712 
642 
405 
677 
537 

458 

680 



670 

468 
580 
53:3 
821 
529 
815 
440 



678 
514 
339 
705 
541 
416 
680 
524 
371 
654 
605 
430 
715 
587 
462 
678 
623 
635 
508 
526 
517 
763 
495 
705 
541 
416 
794 
549 
495 
609 
460 
662 
460 
620 
491 
628 
637 
802 
573 
657 
507 
638 
.521 
737 
641 
775 
546 
791 
577 
805 

^? 
675 

608 

823 

553 



778 
571 
383 
743 
553 
420 
790 
605 
402 
680 
605 
450 
700 
627 
471 
678 
677 
638 
520 
572 
615 
627 
583 



33 



[Inclosure 3.]— Continued. 
Tests of Steel Portland cement — Continued. 





Date. 


Fine. 


Set 
time. 


Propor- 
tion. 


24 hrs. 


7dys. 


Imo. 


3 mo. 


6 mo. 


1 yr. 






No. 


i Ce- 
ment. 


Sand. 


2 yrs. yrs. 

i 
1 


2202 


Oct. 7, 1897 
do 


2.0 


H. 
2 


M. 
00 


1 

100 

i 25 

100 

25 
100 

25 
100 

25 
100 

25 
100 

25 
100 

25 
100 

25 
100 

25 
100 

25 
100 

25 
100 

25 
100 

25 
100 

25 
100 

25 
100 

25 
100 

25 
100 

25 
100 

25 
lOO 

25 
100 

25 
100 

25 
100 

25 
100 

25 
100 

25 
100 

25 
100 

25 
100 

25 
1(K) 

25 
100 

25 
100 

25 


".I. 

75 
"*75" 
■••75- 



75 
■"'75' 
'"75" 
"'75' 
'"75* 
"■75* 
■"75' 
""'75' 
■■■75' 
■■'75* 
"■75' 
"75" 
'"75* 
"75" 
""75" 
'"75' 
■"75" 
'"75* 
■■75' 
""'75" 
'"'75' 
"75' 
■■'75' 
"'75' 
*"?5' 
"*75" 
■'"75' 


2.50 
'"'336' 
""'329' 

'3.52' 

""sis* 

""338" 

*368' 

"'322' 

""m 
""276' 

""218" 

"245" 

348 
275 

'"'ios' 

""378" 

'326" 

■323" 

'265' 

""276' 

""275' 

""235' 

""285' 

""28.5" 

'2O6" 

""i95" 

'"'iiV)' 

■"263' 

■38.5' 

'396" 

"'293' 

""285" 


429 
179 
519 
183 
514 
206 
507 
194 
459 
152 
528 
166 
355 
234 
480 
213 
408 
191 
371 
180 
378 
224 
428 
500 
425 
170 
170 
213 
499 
224 
728 
255 
513 
195 
488 
180 
490 
191 
445 
177 
438 
212 
57(i 
223 
592 
203 
516 
152 
360 
238 
(iOS 
208 
450 
280 
625 
235 


619 
270 
659 
251 
584 
361 
525 
353 
501 
271 
580 
244 
321 
310 
.520 
339 
465 
349 
550 
238 
550 
368 
570 
5.50 
509 
320 
274 
426 
609 
296 
601 
250 
577 
269 
512 
289 
622 
292 
479 
261 
721 
346 
588 
349 
788 
368 
672 
256 
695 
305 
630 
380 
605 
3(K) 


644 
327 
746 
327 
673 
468 
638 
441 
609 
3»8 
590 
374 
575 
418 
648 
448 
490 
449 
552 
322 
410 
360 
552 
550 
492 
387 
382 
516 
770 
376 
670 
293 
623 
403 
546 
386 
670 
354 
632 
384 
656 
436 
707 
503 
663 
457 
690 
330 


735 774 
335 402 
753 761 






2^02 






98bl 


Nov. 14,1897 
... do 


1.9 


2 


15 






9881 


340 
627 
489 
672 
499 
626 
424 
587 
420 
665 
463 
635 
465 
626 
465 


407 






49K8 


June 6,1897 
do .. . 


.6 


1 


20 






4968 




1 


514:^ 


June 11,1897 
..do 


.7 


1 


10 








5142 








5466 


June 19, 1897 
do 


.6 


1 


05 








5466 










June 23, 1897 
do 


.5 





55 








5553 








5617 


June 25, 1897 
do 


.5 





55 


I 




5617 






6261 


June 27, 1897 
... .do 




.6 


1 


00 






6261 






6286 


June 29, 1897 


.8 





55 






6286 


. . .do 


- 




7122 
7122 


July 25,1897 
do 


.5 


1 


25 


669 
415 
557 
434 

507 






7228 


July 29,1897 
, . . do 


.3 





35 






72'''8 






8711 


Sept. 21, 1897 
.do 


.5 





3.5 


1 





8711 






9055 


Sept. 27, 1897 
do 


1.4 


1 


30 


538 
436 
560 
538 
812 
517 
697 
433 







9055 






9101 


do 

... .do 


2.8 





45 






91()1 






4221 


Dec. 3, 1897 


1.2 


1 


50 








4221 








1 


Juno 3,1898 
do 


2.2 


1 


25 








1 








2 


Nov. 1,1898 
do 


i.8 


1 


50 


599 
427 
690 
464 
735 
477 
650 








2 








3 


Dec. 27,1898 
do 


2.4 


1 


35 









3 








4 


Dec. 1,1899 
.. . do 


3.0 


1 


50 








4 








5 


Mar. 5,1899 
do 


2.4 


2 


00 








5 


445 
721 
544 
649 
559 








6 


May 6,1899 


3.2 


1 


50 









6 








7 


June 3,1899 
do 


1.7 


1 


45 








7 








8 


June 1,1899 


1.4 


2 


10 








g 










-6988 


June 20, 1899 
do 







45 


1 .. . 


.,,,.. 




6988 








2-1 


Oct. 29,1899 
.... do 


2.2 


3 


25 








2-1 










2-1 


Nov. 13, 1899 
do 


1.6 


1 


30 










2-1 




1 






11 


Nov. 6,1899 
do 


3.0 


1 


00 




1 






1 1 




1 






11 


Nov. 9,189f) 
do 


2.2 


1 


00 










1 1 






1 






2 1 


do 

do 


2.0 


3 


35 


625 
227 
602 
220 
553 












2 1 












11 


Dec. 7,1899 
do 


2.0 


1 


50 












11 












2-1 


Dec. 19,1899 
do 


2.4 


1 


(K) 












2-1 


233 





























34 

Appendix 2. 

Letter of the president of Illinois Steel Company to Major Marshall. 

Office of Presidext, 

Illixois Steel Compaxy, 

"The Rookery," 
Chicago, March 21, 1900. 
Dear Sir: With further reference to your investigation of our 
Steel Portland cement, I herewith submit copies of the letters patent 
Xo. 544,706, granted to Jasper Whiting and subsequently conveyed 
to the Illinois Steel Company, covering the process of our Steel Port- 
land cement manufacture; also copies of letter of Mr. Whiting, 
manager of the cement department, to Major Adams, engineer in 
charge of the Plaquemine work, setting forth our claims for the 
Steel Portland cement. 

Yours, very truly, 

E. J. BUFFIXGTOX, 

President. 
Maj. W. L. Marshall, 

Corps of Engineers, U. S. A., 

Chicago, III. 



[Inclosure 1.] 
UrsIIXED STJVTES F^A^TENX Oi^KICEi. 



Jasper Whiting, of Chicago, Illixois. 



MANUFACTURE OF CEMENT. 



Specification forming j^cLrt of Letters Patent Xo. 544,706, dated August £0, 1895. 
Application filed February 5, 1895. Serial Xo. 537,404. {No specimens.) 



To all whom it may concern: 

Be it known that I, Jasper Whiting, residing at Chicago, Cook county, Illi- 
nois, have invented a certain new and useful Improvement in the Manufacture 
of Cement, of which the following is a specification. 

My invention has for its object the manufacture, mainly from blast furnace or 
other slags, of a cement which shall be equal in quality to the best Portland or 
other similar cement, and which shall at the same time be more economical of 
manufacture. In my method I have ob^i.ated the necessity of calcining the com- 
pound or in any manner continuing the heating or of reheating the same, except- 
\ ing that for drj^ng purposes, whereby a consequent savingin expense is obviously 
V obtained without detracting from the character and quality of the product. 
Slag is x)ractically inexhaustible in supply, and when after proper treatment, as 
hereinafter set forth, it is combined with one or more other elements it forms a 



valuable factor for a cement of superior quality and durability ; and my inven- 
tion consists in the following-described process : I prefer to use the molten slag 
direct from blast-furnaces and a-< it runs therefrom to bring it into contact with 
water in any suitable manner and in such quantity that the material is completely 
chilled. By the action of the water the slag becomes disintegrated and is reduced 
to a porous, spongy, or sandy condition. This material is thoroui^hly dried and 
is intimately mixed with slaked lime and caustic soda, potash, sodium chloride, 
or equivalents, or any substance of which the latter are ingredients. It ^nll be 
understood, therefore, that when I use the term ' ' soda " or " caustic soda " in 
the claims or elsewhere I intend to include potash and all similar substances 
giving the same effect. The proper proportions of the lime and soda are depend- 
ent upon the chemical character of the particular slag used, which is to be deter- 
mined by analysis. The whole mass is then ground to extreme fineness and is 
then ready to be packed in bags or barrels for the market without calcination or 
heating whatever. 

The amount of slaked lime and caustic soda (or equivalent) to be added de- 
pends upon the composition of the slag used, as hereinbefore stated. The amount 
of slaked lime added will therefore vary between nothing and thirty per cent 
of the finished product, according to the basicity of the slag used, and in the 
case of the caustic soda from one eighth per cent to three per cent of the chem- 
ically-pure article, depending chiefly upon the use for which the cement is 
intended. 

The caustic soda may, if desired, be added to the slaked lime in an aqueous 
solution and the resulting mixture dried before incorporating it with the slag, 
or it may be added in a dry state to the slaked lime, or the three materials may 
all be mixed in some proper machine. Jf desired, however, they may all be 
admitted practically unmixed into the grinding-machine and thereby become 
intimately associated, the one with the other, in the process of reduction. If it 
is desired to use certain pulverizing-machines, the materials may be mixed after 
the grinding or pulverizing process and before packing for the market. 

A cement possessing hydraulic qualities may be i)roduced from certain slags 
by the addition of caustic soda (or equivalent) alone in the in-oportion above 
described, but the quality of the product will generally be improved by the addi- 
tion of some slaked lime. It is seldom necessary that more than two per cent of 
chemically- pure caustic soda (or equivalent) need be used and for ordinary pur- 
poses a smaller amount will be found sufficient. The presence of the caustic 
soda renders the resulting cement much stronger and (juicker setting, and by 
varying its proportions a cement of any desired (luality can bo obtained. The 
action and purpose of the caustic soda in my process may be stated as follows : 

Slag, chilled in water is only slightly soluble in water or milk of lime, and the 
action between it and the slaked lime is therefore very slow. A briciuette made 
of this material shows in twenty-four hours only one hundred and fifty pounds 
per scpiare inch tensile strength. When caustic soda or etjuivalent is added in 
the manner described above and water added to the dry cement, the soda dis- 
solves and an alkaline solution is formed which readily attacks the slag, forming 
a silicate of soda. This in turn is immediately broken up by the action of the 
lime present, a tricalci(r silicate or cement being formed, and the soda is set free 
to act on more slag. In this manner by acting as a sort of medium or carrier it 
helps the lime and slag to (luickly unite to form a cement. A briquette made in 
the way described will after twenty-four lumrs show as liigh as nine luuidrod 
and twenty-five pounds per s(|iia.rt' iiicli t(Mi.sil(» strength. 



'66 

"While I am aware that the idea of mixing chilled slag with slaked lime to 
form a cement is not new and that soda has been added to ordinary c;ilcined 
Portland cement, still I am not aware that caustic soda or its equivalent or sub- 
stitute has been added to slag -cement for the purpose and in the manner above 
described. By the peculiar action of the soda, as set forth, I am enabled to pro- 
duce a quick setting cement of great strength and high hydraulic properties and 
obtained mainly from blast-furnace or other slags without calcination or other 
application of heat. 

If it is desired to immediately form the composition into bricks or refractory 
materials with or without comprespion, the soda in solution, with or without 
slaked lime, may be added to the slag which has been previously chilled in 
water. If a particularly fine quality of brick is required, the slag may be passed 
through a gi'inding-machine either before or after its incorporation with the soda 
with or without the addition of slaked lime. These bricks may be colored^ by 
the proper ingredients added thereto, such as iron ore, &c., or they may be vitri- 
fied in any of the ordinary methods, such as by immersing in a solution of brine 
or other materials and subjecting to heat. 

I claim — 

1. The method of manufacturing cement from slags which consists in chilling 
molten slag in water, drying and grinding the product and adding thereto caustic 
soda or its equivalent in a dry state. 

2. The method of manufacturing cement from slags which consists in chilling- 
molten slag in water as it comes from the furnace, drying and grinding the slag 
and adding thereto slaked lime and caustic soda both in a drj^ state and in the 
proportions substantially as set forth. 

3. A cement composed of blast furnace or other slag in a dry pulverized form 
and caustic soda in a dry state, in substantially the proportions set forth. 

4. A cement composed of blast furnace or other slag in a dry pulverized form 
and caustic soda and slaked lime in a dry state and substantially in the propor- 
tions set forth. 

Jasper Whiting. 
Witnesses: 

Samuel E. Hibben, 

E. Nemett. 



[Inclosure 3.] 

Letter of manager of cement department, Illinois Steel Company, to Major 

Adams. 

Sir : In order to facilitate your investigations of Steel Portland cement, now 
being used in the construction of the Government locks at Plaquemine, La. , I 
respectfully beg to submit the following brief outline of the history of the ma- 
terial, of its commercial standing to-day, and of our reasons for believing that it 
fulfills in every particular the requirements of the specifications of the work in 
question, 

Portland cement derived its name from its resemblance, when allowed to 
harden, to the famous building stone found near Portland, England. The origi- 
nal patent covering this material was obtained in 1824 by an Englishman named 
Joseph Aspdin. I quote therefrom : 

"My method of making cement which I call Portland cement is as follows: I 
take a specific quantity of limestone and calcine it. I then take a specific quan- 
tity of clay and mix them with water to a state approaching impalpability. After 



37 

this proceeding I put the above mixture into a slip pan for evaporation until the 
water is entirely evaporated. Then I break the said mixture into suitable lumps 
and calcine them in a furnace, similar to a lime kiln, until the carbonic acid is 
entirely expelled; the mixture so calcined is to be ground to a fine powder and it 
is then in a fit state for cementing. This powder is to be mixed with a sufficient 
quantity of water to bring it into the consistency of mortar and thus applied to 
the purpose wanted." 

The method of making Portland cement therefore is plain and simple, but 
if the definition of Portland cement as outlined in the original' patent papers 
covering this material be literally followed there would be no Portland cement 
manufactured to-day. The double calcination mentioned in the patents was dis- 
continued shortly after the material was produced, but the material itself con- 
tinued to be manufactured in rapidly-increasing quantities until it has assumed 
the most important place among hydraulic materials. 

There are, indeed, at the present time several methods of manufacture: The 
so-called dry method, the so-called wet method, the so-called semidry method, 
the method which employs limestone and clay as raw material, and methods 
which employ other materials containing the constituent elements of limestone 
and clay, but which are neither one nor the other. Moreover, Portland cement, 
was originally given the name mainly to distinguish it from ordinary domestic j 
or natural cements which were nothing more nor less than the calcination ofV 
natural cement rock or impure limestone ; if, therefore, the definition of Portland 
cement as originally given should hold true to day then there are various manu- 
facturers of high-grade hydraulic materials, being sold as Portland cement 
throughout this country, who are misrepresenting their article. I refer to those 
cement manufacturers who, according to their published statements, do not 
form their products by a mechanical admixture of limestone and clay, but 
by a calcination of natural cement rocks. If the definition as given above is 
correct, then these must be classed as "natural" cements, and not as Portlands, 
and sold in competition with low-grade materials to which they are evidently 
vastly superior. I believe, and it is the well-known opinion of exi)erts on 
hydraulic material, that some of these cements, at least, are of a quality nearly 
if not quite ecpial to the best German and English brands in the market, and it ) 
would be manifestly unfair to dis(iualif y them because the method they take to j 
reach a certain result is different from that of their various competitors. Their 
product fulfills the ordinary specifications for Portland cements, and therefore 
we claim that they should, like ours, be termed Portland. 

I (luote from a treatise on cement from a celebrated English authority — Reid: 

' ' Wide as the field of selection is from which may be obtained all the necessary 
materials for the manufacture of Portland cement in its various geological for- 
mations and which may be regarded as the natural supply, there are still to be 
found valuable supplies of an artificial character, of which we may select as 
most noteworthy the slags of various kiiids resulting from iron making and other 
alli(id industries. The analysis of this slag is usually f^avorablo as a cement-mak- 
ing agent, from the high percentage of lime it contains." 

Furnace slag is largely composed of decarbonized limestone. This limestone, 
l)rimarily placed in a furnace to fiux the iron ores, is often taken from tlu' same 
quarries which furnish the rock from which Portland cement is made by the 
older methods. In the one instance, limestone unites with the argillaceous ma- 
terials of th(» ores and is fused to a cinder; in the other caso, the limestone is 
sintered with tlui clay, \vhi(;h is addiMl arlidcially. The resulting suh^tMiico^ :\vo 



38 

extremely similar with the exception that the furnace slag is somewhat lower in 
limie. In the manufacture of Steel Portland cement this deficiency of lime is 
added mechanically to.2:ether with a small quantity, less than 1 per cent, of caustic 
soda to render the material quicker setting. The resulting cement fulfills all 
ordinary specifications for high-grade Portland. 

While we admit that cements manufactured from slag in foreign countries 
are, as a rule, inferior in quality to the best cements manufactured by the older 
processes, and while I do not wish to hide the fact that European Portland cement 
manufacturers have combined against the recognition as Portlands of cements 
made from slag, still I maintain that in many other branches of industry Ameri- 
can terms and definitions do not agTee with those of Europe, and I believe that 
/ there is good reason for maintaining that here in America the best of the puzzo- 
[ Ian or slag cements of Europe have long been considered as Portland cements 
"^ot only by some of the best known cement experts of the country, but by the 
United States Government as well. 

The most prominent cement manufactured from blast-furnace slag upon the 
American market during the past ten years has been H. H. Meier's Puzzolan 
cement, a material manufactured in Germany and known chiefly for the very 
unusual quality it possesses of not staining stonework. This cement first came 
into prominence when it applied for recogiiition with the various high-grade 
Portlands of the world as a suitable material to be used in the construction of a 
great waterworks system in St. Louis, which undertaking required the use of 
several hundred thousand barrels of the highest grade Portland cement obtain- 
able. After a long series of tests, conducted over a period of several years, this 
cement, pre^i-ously unknown, practically speaking, was selected for the v.^ork, 
j- and in a recent conversation which I had with a prominent engineer connected 
with the undertaking, he stated that after several years' experience with it, both 
practically and theoretically, he considered Meier's Puzzolan cement equal to any 

. brand in the market. 

That the Government also considers this cement not only equal to Portland, 
but a Portland, considering the word in its generic sense, is proved by the fol- 
lowing extract taken from specifications of one of the most important federal 
/ structures now being erected : 

"All cement used in setting granite or in work m contact with the granite 
work will be a Portland non staining cement equal to the La Farge or Meier. 
* " * Cement to be acceptable must pass the following tests, etc. " 

It is evident, therefore, from these two examples that the United States Gov- 
ernment through its representatives as well as prominent hydraulic material 
experts considered the words Portland and puzzolan as related to cements in- 
terchangeable, both denoting a hydraulic material capable of fulfilling certain 
stated specifications. 

When the cement manufactured by the Illinois Steel Company was first placed 
upon the market the question as to whether or not it could rightly be called a 
Portland at once became a matter of importance. It was recognized that in cer- 
tain of its characteristics our material differed from ordinary- Portland cements, 
but it was also recognized that these characteristics did not in any way interfere 
with the value of the material for the majority of uses. It was, therefore, decided 
to regard as the definition of Portland that already accepted by the United States 
/' Government as a hydraulic material, fulfilling certain recognized specifications. 
In other words, we took the ground that it was not important how the resulting 
material was obtained, provided the material would fulfill certain specific re- 



39 

quirements, those requirements being identical with those of recognized Port- 
land the world over. The main difficulty in our material fulfilling this definition 
lay in the matter of specific gravity, but in this point also there were many prece- 
dents, notably that of the Meier Puzzolan cement, to show that specific gravity 
was not an essential feature, and it was decided to disregard this point. This 
decision was arrived at only after careful consideration, and in the advertising 
matter issued in the interests of our material we state distinctly that the material 
is made from slag and that it is of specific gravity somewhat lighter than ordinary 
Portland. 

It has been claimed that a cement manufactured from slag should not be 
termed a Portland, for the reason that it is not suitable for all classes of work, 
notably exposed work in dry air. In our pamphlets advertising our product we 
admit this to be true to a certain extent, but because this is true is no reason, we 
believe, why our material should not be considered a Portland for the uses for 
which it is suitable. There are few cements suitable for all classes of work, some 
being more hydraulic than others, some slow setting, some quick setting, some 
are stainless while others are not, and some give far better results in dry work 
or in work exposed to the action of sea water than do others, yet all are termed 
Portlands because they are made by a certain process, whereas none of them, 
broadly speaking, will fulfill the work of all. We have never represented our 
product, so far as I know, to be a sidewalk cement or a cement suitable for use in 
thin layers where the material is exposed to the drying influence of the atmos- 
phere, but we have maintained and do maintain that for heavy concrete and 
masonry work it fulfills all the requirements of the older brands of Portlands, 
and therefore should be considered a Portland. 

It is also claimed that Portland cement sets in one-half hour to a maximum of 
eight hours, while cement made from slag, according to Professors Tetmajer and 
Candlot, takes from eight to ten hours and sometimes much longer. This may 
be true of the ordinary cements made from slags in Germany, but it is easily 
X)roven that Steel Portland cement has its initial set in about one hour and final 
set in approximately three hours, corresponding in this respect very closely to 
the ordinary Portland cements. It is also claimed that sulphur in the form of 
sulphide is a most dangerous ingredient. In reply to this I will cite the opinion 
of Professor Tetmajer, who is acknowledged by all to be the leading authoritj'^ on 
slag cements in the world : ^^--^ 

"That sulphur in the form of sulphide running as high as 3 per cent is not 
injurious to the material." 

The sulphur in the form of sulphide in our material is but little over 1 j)er 
cent, and we have as yet no reason to believe it is injurious in that proportion. 
To x)i'ove this beyond a doubt. Prof. L. W. Wilkinson, in charge of the chemical 
department at Tulane University was retained by the Illinois Steel Company to 
investigate this matter. After a searching investigation covering a year and a 
half he submitted a report, copy of which I app(>nd, in whicli he stacos distinctly 
that so far as he has gone the sulphur has undergone practically no change in the 
material. To further substantiate this statement, I will say that I have in my 
possessicm a bri(|uotte made from a sample of the slag cement used fiftt>on yivirs 
ago in the construction of tlie docks and waterworks at JNlainz. Gt>rniany, which 
bricpiette is to day in first-class condition. This sample was given me witliin the 
last few months by an American engineer, who made a ])ersonal examination of 
the work in (luestion and who stated to me in writing tliat the work itself is in 
the best condition. This cement contains considerably more sulphur than does 



40 

the product which we are manufacturing, and is ample proof in our opinion that 
under the conditions in which we recommend our material to be used, sulphur, 
at least in the proportions in which it exists in our material, is not a haiToful 
ingi-edient. 

It seems to be unif ormly admitted by all practical men that the essential in a 
Portland consists of three things : Strength in practical work, stability of lasting 
qualities, and uniformity. That our material fulfills the first requirement is 
proved by the fact that it stands the tests specified for work of the greatest im- 
poitance. 

That it fulfills the second requirement is proved not only by the fiiteen-year- 
old briquette mentioned above and the excellent condition of our own first work, 
now five years old, but by steam tests of the greatest severity, conducted by 
numerous experts throughout the country. One of these tests consisted in plac- 
ing samples of our material and similar samples of a recognized and well-known 
brand of Lehigh Valley Portland cement in a cage in the drum of a boiler operated 
under one hundred pounds pressure for a week. At the end of that time the 
briquettes were removed and tested for tensile strength on a Riehle testing 
machine. The briquettes of the Lehigh Valley Portland cement averaged a 
tensile strength of 1,430 pounds while the briquettes of our own material aver- 
aged 1,435 pounds. In other words both materials stood most satisfactorily this 
severe test. 

The thii'd requirement, that of uniformity, we believe we have solved better 
than any other manufacturer of high-grade cement in the market. The greatest 
care is taken not only in the selection of ores to make a slag of a certain compo- 
sition, but also to select fi*om the furnaces making this slag only such material 
as is exactly suited far oui' purposes. Grood cement can not be made from inferior 
slag any more than it can be made fi'om inferior rock. After each car of this 
material is made an average sample is selected, the proper mixtures made, and 
the same gi'ound in a miniature mill where actual cement is produced. The 
cement is tested one week before the main body of the material is used and in 
this way practical tests are obtained. In addition to this, the cement is constantly 
tested whilst being manufactured. There is no danger of cracking due to free 
lime in our product, because there is no free lime present, while the unsurpassed 
degi'ee of fineness to which it is ground insures great strength in practical work. 
To sum tip. it does not seem fair to us nor to the building community in general 
to force the establishment at great expense of time and money of a new term to 
signify the product which we manufacture, mainly because the means we have 
taken in arriving at a certain result are different from those previously taken 
by older manufacturers. The essentials of our process are not secret. We 
believe our product to be a Portland, considering that word in its generic sense, 
and as much superior to ordinary cements as steel is to ii'on. It would seem to 
be just as fair to have forbidden the original manufacturers of steel under the 
Bessemer process to call their article steel, simply because their process had not 
previously been in vogue among manufacturers of material. 

Steel Portland cement was first manufactured in Chicago at the Xorth Works 
of the Illinois Steel Company in 1894. The cement fii'st made was used in the 
foundarion of a grinding machine erected in oui- plant, and is to-day an evidence 
of the fact that the material does not disintegrate and is a safe and reliable 
cement to use. This plant is still in operation and has been constantly increased 
in size until it now has a cax)acity of '200,000 baiTels per year. Moreover, so gi-eat 
has been the success attending this first plant that a new plant, having the capacity 



41 

of 500,000 barrels per year, is now in course of construction. Unlike other manu- 
facturers, the Illinois Steel Company makes but one grade of cement — Steel Port- 
land cement. In the early stages of its manufacture, when there was great 
prejudice against it, numerous overtures were made by dealers to purchase the 
material with a view to disguising it by coloring matter or by placing it in 
barrels under false label, but in no case was this done, as the manufacturers not 
only had the greatest faith in the future of the material, but their reputation as 
large producers of steel of the highest quality rendered it unwise for them to 
use underhand methods of introduction were they so disposed, which they were 
not. The Illinois Steel Company were pioneers in this country in the manufac- 
ture on a commercial scale of high-grade cement from blast-furnace slag. The 
success of its product has. been largely aided by the conservatism in which it was 
introduced. As already stated, the material was subjected for two years to the 
most severe practical and theoretical tests bef oi'e it was placed upon the market, 
for the company not only realized its responsibility to the building trade in gen- 
eral in vouching for a new cement, but it did not wish to jeopardize its other and 
greater interests by fathering material which was not worthy of its established 
reputation. It therefore not only tested the material for two years and used it 
in its own construction, but sent an experienced engineer to Europe to discover, 
if possible, any fundamental errors in its chemical composition. This engineer 
reported that cement of the highest grade had been made from slag, but that the 
slags of Europe were so irregular in composition as to explain fully the untrust- 
worthy character of the foreign slag cements. These irregular slags are the 
natural results of the low-grade irregular European iron ores which are smelted, 
and is a condition which will never be overcome, except possibly in a few isolated 
instances. With our Lake Superior ores, our Connellsville coke, and our lime- 
stone, especially selected for the purx)ose, the situation is very different, and, as a 
result, our cement is at all times the equal of the best European cements made 
from slag and is always uniform. Since this introduction the Illinois Steel Com- 
pany has used the material exclusively within its own works in erecting machinery 
and structures aggregating in value over §5.000,000, thus proving its own faith 
in its product. 

I append hereto original telegrams received from various engineers of promi- 
nence asking for their opinion of Steel Portland cement. The vocations and 
addresses of the individuals are indicated on the telegrams themselves, and should 
you desire to ascertain more fully the results of their experience with our prod- 
uct, I feel sure they will gladly furnish what information they can. I also 
append an average of the tests which have been made on the Steel Portland 
cement already delivered to the Pla(iuemine work. The tests cover approxi- 
mately 17,000 barrels. I also append copies of reports of tests, both chemical and 
physical, on our cement, made by experienced, unprejudiced experts, which prove 
that the statements made in regard to it are well founded. Moreover, I wish to 
imi)ress upon you that we make but one grade and that all material leaves our 
works in the original package ; it is never sold under a false name. Bofort^ making 
a price to Stewart & Co., on the Plaquemine work, three of our representatives 
saw Major Qninn at different times and obtained from him verbal acce])tance of 
our material, " provided it showed the strength recpiirod in the specitii-ations." 
I personally asked him the direct question, whether the niatcu'ial in a generic 
sense was acceptable' to him, and ho ro])lied that it certainly was. that ^Nfajor 
Thomson had made preliminary tests of it. and the results were highly satisfac- 
tory. We then entered into a contract with Stewart ifc Co., by which we agreed 



42 

to furnish the entire cement for the work, and we further guaranteed that 
this cement would fulfill specifications of the conti*act : we could safely do this, 
as Major Quinn had given his consent to the material in a general way, and we 
were perfectly convinced that so far as the detailed specifications were concerned, 
our material would not only fulfill but would very much exceed them. We have 
already placed some 17,000 baiTels of cement in the work, and so far have received 
no complaint whatever of the character of the cement or of the concrete made 
therefrom. 

TVe therefore respectfully request, as large quantities of the material have 
been sold for use in this work now under your direction, that you make a thorough 
investigation as to its quality. I would further say that any aid which the 
Illinois Steel Company can give you in hel^Ding to arrive at a just conclusion in 
this respect will be cheerfully furnished you. We invite you to go to Chica-go, 
either personally or through a representative, and make a searching examina- 
tion, not only into our plant and methods of manufacture, but into the care 
which we take in testing material thoroughly before sending it out in order to 
provide against irregularities. We will throw the doors of our plant wide open 
to you and will show you all of our books and will gladly furnish any informa- 
tion that will be of aid to you. 

We trust you will realize the far-reaching importance to us of this matter. 
Not only is the Plaquemine work involved, but the effect of any action you may 
take on our material at this time will have a very serious influence on our inter- 
ests at other points throughout the country. We have investigated Steel Port- 
land cement for six years. We have shown our faith in the material by the 
expenditure of several hundred thousand dollars in the construction of a new 
plant. We know it to be a safe, reliable, high-grade material and we court 
investigation. Therefore, we respectfully request that you make a careful exam- 
ination of our cement and when this is done we ask that you advise us of the 
results of your investigation. 

Yours, very truly, 

Jasper Whitixg, 

Manager Cement Department. 

H. 31. Ada:m5, 

Major, Engineers, U. S. A., Xeic Orleans, La. 



[Telegrams.] 

Chicago, III. , December 19, 1899. 

Jasper Whitixg, care Illinois Steel Co. , Xew Orleans, La. 

We consider Steel Portland cement a high-gi-ade Portland for heavy under- 
ground work. 

DiCKMAX & Mackenzie. 

Independent Chemists, ^Metallurgists, and Testing Engineers. 



Xew York, December 8, 1899. 

Mr. Jasper Whitestg, Illinois Steel Co., Chicago, 111. 

Richardson very favorable to material : will recommend same if Adams wiites. 

Chas. W. Hall. 

XoTE.— Refers to Clifford Eicliardson. as aiithoritv on cements. 



43 

Bay City, Mich., December 19, 1899. 
Jasper Whiting, Hennen Building, New Orleans, La. 

Have used over seven thousand barrels of Steel Portland cement on heavy- 
engine foundations and other heavy work and find it a most suitable and high- 
grade Portland cement for that purpose. 

North American Chemical Company. 

Note.— This is self explanatory- 



New York, December 19, 1S99. 

Jasper WhitIxNG, Hennen Building, New Orleans, La. 

I have used Steel Portland cement, manufactured by Illinois Steel Companj^ 
on several jobs where heavy concrete in large masses has been required, founda- 
tions in some cases being 10 feet deep and about 12 feet wide and over 100 feet 
long, and have found it equal to other high-grade Portland cements. Can 

indorse it for any high grade work. 

James C. McGuire, 

Consulting Engineer. 



Chicago, December 19, 1S99. 

Jasper Whitixg, Hennen Building, New Orleans, La. 

Have had splendid results with Steel Portland cement concrete, proportions 

one cement, four sand, six crushed stone for heavy foundations requiring 5,000 

barrels. Proportions prove quality of cement. 

E. Lee Heidenreich, 

Consulting Engineer. 



Chicago, December 19, 1899. 
Illinois Steel Company, care Jasper Whiting, New Orleans, La. 

Have used several thousand barrels Steel Portland cement in concrete during 

past four years with very satisfactory results. 

W. S. Dawley, 

Chief Engineer, C. d- E. I. R. R. 



Chicago, III., December 19, 1899. 
Illinois Steel Company, New Orleans, La. 
Unquestionably. 

ChAS. GOLDSBOROKiH. 

NoTK.— This telegram in answer to (luestion : "Do you consider Steel Portland cement a 
high-grade Portland for heavy concrete work?" Mr. Goldsborough has used several thousand 
barrels. 



Chicago, III., December 1 9, 1899. 

Jasper Whiting, Illinois Steel Co., New Orleans, La. 

Your telegram even date. I hii\o been using for xmst three years in all heavy 
concrete work, Portland cement mannfitctured by th(> Illinois Stoel Company with 
perfect success. I consider it e(puilly us good as imported Portland, 

F. E. Paraius. 
Chief Engi II i'cr, (\ T. T. li. U. Co. 



Chicago, III. , December 19, 1899. 

Mr. Jasper Whiting, Hennen Building, New Orleans, La. 

We consider Steel Portland cement a high-grade Portland for heavy concrete 
work. 

E. F. GOBEL Co. 
Note.— Prominent Chicago contractors. 



Chicago, III. , December 19, 1899. 

Jasper Whiting, care Illinois Steel Co., Hennen Building, New Orleans, La. 

Steel cement used for a number of years. Concrete where subsequently exam- 
ined in fine condition. 

S. J. Larned, 

Suj)t. Chicago Telephone Co. 

ISToTE.— This is the opinion of our first customer. 



Pittsburg, Pa. , December 19, 1899. 
Jasper Whiting, Illinois Steel Co. , New Orleans, La. 

From the tests of prominent unbiased experts and from actual results obtained 
during past four years I consider Steel Portland cement unexcelled for heavy 
concrete work, especially under ground or water. 

F. S. ViELE, 

Supt. Standard Underground Cable Co. 



Lafayette, Ind., December 19, 1899. 
Jasper Whiting, Illinois Steel Co., Hennen Building, New Orleans, La. 

Steel cement strength and fineness especially adapted for concrete. My expe- 
rience with same very satisfactory. 

W. K. Eldredge, 

City Engineer. 
Note.— This after using 8,000 barrels. 



Chicago, III., December 20, 1899. 
Jasper Whiting, Hennen Building, New Orleans, La. 

We have used Steel Portland cement lar^gely for heavy building and engine 
foundations and found it first class in every respect and use nothing else. 

Chicago Shipbuilding Company. 

Note.— The most prominent inland shipbuilding concern. 



Chicago, III., December 19, 1899. 
Illinois Steel Company, Hennen Building, New Orleans, La. 

Steel Portland cement a high-grade cement for heavy concrete work; have 
used this season 5,000 barrels of it in this city. Work is excellent. 

T. Nicholson & Son Company. 

Note.— Prominent Chicago and New Orleans contractors. 



45 

Louisville, Ky., December 19, 1S99. 
Jasper Whiting, care Illinois Steel Co. , New Orleans. La. 

We consider Steel Portland cement one of the high-grade brands for heavy 

concrete work and masonry use. 

M. T. Lewmax & Co. 

Note.— Prominent contracting engineers. 



New York, December 19, 1S99. 
Mr. Jasper Whiting, Illinois Steel Co., New Orleans, La. 
Have used large quantities Steel Portland cement. Consider it best Portland 

cement in market. 

V. J. Hedden & Sons. 

Note.— Prominent New York contractors. 



[Letters.] 
Stone Brothers Co., Ltd., Architects, 

New Orleans, La., December 19, 1S99. 

Dear Sir : Answering your inquiry, we used several hundred barrels of Illinois 
Steel Company's Steel Portland cement in foundations of Tulane and Crescent 
Theatres in this city during the spring of 1898. 

The mortar was mixed in proportion of one part cement to two and one-half 
parts sand. 

The material gave very good satisfaction and we consider it a high-grade Port- 
land cement. 

Yours, very truly. 

Stone Brothers Co., Ltd. 

By Sam Stone, jr. 
Mr. Wm. W. Bierce, 

General Southern Agent Illinois Steel Co. , 

Hennen Building, Neiv Orleans, La. 



Tulane University of Louisiana, New Orleans, 

College of Technology, Sugar Chemistry, 

February 27, 1S99. 
Dear Sir : At your request I have examined some of the briquettes made by 
Professor Creighton, and which have been under water from three to four 
months to about one and a half years. So far as my investigations have gone I 
find that the sulphur is practically unchanged. 
Yours, very truly, 

L. W. Wilkinson. 
Mr. J. G. Bergquist, 

Supt. Cement Department, Illinois Steel Co. 



New Orleans, La., Dccoubcr x^o, 1S99. 
DEAii Sir: In our contra(;t for the drainage work of New Orleans we liave 
used over 00,000 barrels of your Steel Portland cement with very satisfactory 
results. In our o])inion it is a reliable Portland for lieavy concrete. 
Yours, truly, 

Tiik Nation a I, Contuacting Com pan v. 

Eugene Klapp, Manuitcr. 
W. W. Biekck, 

Agent Illinois Stcrl Co., Cilij. 



■46 



The Xatio^ml Contracting Comp,iny, 

Engineering Department, 

Room 713 Hennen Building, 
New Orleans, La,, December 19, 1S99 

Dear Sir : Referring to your favor of the IStli, asking for some information 
relative to the cement used in the foundation work at Pumping Station No. 2, 
would advise that the bricks were laid in mortar, composed of one part cement 
to three parts sand, and the concrete was made with one part cement, three parts 
sand, and a sufficient quantity of lake shells to fill all voids. The work was done 
at different times between February, 1899, and June, 1899. 
Yours, very truly. 

The National Contracting Company, 

L. W. Brown, Engineer. 
William W. Bierce, 

11th Floor, Henneii Building, City. 






Average tests of Steel Portland cement used in Government locks at Plaquemine 

La., December SO, 1899. 

Tensile strength in pounds per square inch after— 



ment to saiiu (,uy 
Yolnme). 


oriquetLes 
broken. 


1 day. 


7 days. 


30 days. 


60 days. 


90 days. 


Neat 

1 cement, 2 sand* . 


1,015 
61 
12 . 


261 


159 
228 
158 


521 . 
326 


389' 


437 


1 ffiment, R sand* . 1 













* River sand used. 



Tests of Steel Portland cement. 

DiCKMAN & Mackenzie, 

Mining Engineers, Assayers, Chemists, 

AND Metallurgists, Chicago, 

Gentlemen : Below find report upon sample of Steel Portland cement tested 
at the order of Mr. Graham, of D, H. Burnham & Co., The Rookery, Chicago, 



Fineness 


Set hard in — 


Tensile st 


rength in pounds per square inch 
after— 


Remarks. 


per cent on 
sieve. 


Xeat. 1 cement- 


-3 sand. 




21 hours. 


7 days. ^ 21 hours. 


7 days. 


Boiling test. 


2.8 


2 hrs. 25 min. 


290 
290 
265 
2.50 

305 


560 105 
535 150 
56<D 160 
480 135 
510 115 


a35 
310 
310 
310 
:320 


This test allowed to 
stand in air and 
th en boiled for two 
hours showed no 
disintegration. 



Illinois Steel Company, 

Cement Department, Chicago, III. 



DiCKMAN & Mackenzie, 

Per H, T, Murray. 



47 

Robert W. Hunt & Co., 
Bureau of Inspection, Tests, and Consultation, 

Chicago, September 26, 1899. 

Gentlemen : We beg to submit the following report on six samples of Steel 
Portland cement, sampled at the reijuest of Mr. Bergquist, from stock at the 
North Works, September 18, 1899: 



Fine- 
ness per 


Initial set. 


Sample 
No. 


Tensile strengrtli 
in pounds per square 
inch after- 
Sam] )le 


Tensile strength 

in pounds per square 

inch after— 


cent on 
No. 100 




Neat cement. \ 


1 cement to 3 sand. 


bieve. 


Hours. 


Minutes 


24 hrs. 


7 days. 


28 days. 


24 hrs. 


7 days. 

269 
258 
247 
221 
202 
212 


28 days. 


100. 




50 


1 
2 
3 
4 
5 
6 


318 
310 
279 


563 
.512 
. 514 
498 
495 
514 


569 i 1 
540 ^ 2 
670 3 
499 4 
552 5 
576 6 


124 
115 
129 


366 






408 
320 
408 








378 








361 











Figures are averages of three briquettes. 

The neat briquettes were made with about 19 per cent of water, and were 
tamped into the moulds with the handle of the trowel. The sand briquettes were 
made with about 9 per cent of water, using three parts of torpedo sand to one 
part of cement by weight, and were also tamped into the moulds with the handle 
of the trowel. 

We remain, yours, truly, 

Robert W. Hunt & Co. 
Illinois Steel Company, The Rookery, Chicago. 



Tests on Steel Portland cement made by Booth, Garrett & Blair, Philadeljohia, 

October 9, 1807. 



Proportion by 
volume. 


Per cent 

of 
water. 


Tensile strength in 
pounds per square inch. 


Fineness. 


7 days. 


28 days. 

543 

238 


100 per cent passes No. 50 sieve. 


Neat 

1 cement to 3 sand 


22 

11 


457 
143 


99.8 per cent passes No. 74. sieve. 
99 per cent passes No. 100 sieve. 
95 per cent passes No. 200 sieve. 



Tests on Steel Portland cement. 

Office of Water Commissioner, St. Louis, 

M. L. HoLMAN, Commissioner. 





Tensile strength in pounds per square inch after— 




7 days. 

495 
193 


14 days. 


21 days. 


28 days. 


3 months. 


6 months. 


Neat 


521 
201 


535 
236 


559 
221 


527 
2ti6 


699 


1 cement to 3 sand 


276 







All figures are averages. 



48 



Tests on Steel Portland cement, made by Lathbury, Spackman & Bache, Phila- 
delphia, November 19, 1SV7. 



Proportion 
by volume. 


Per 

cent of 

water 

to 

weight 
of ce- 
ment. 


Initial setting 
time. 


Final setting 
time. 


Tensile strength in 

pounds per square 

inch. 


Compressive 
strength in 
pounds per 

square inch. 


Cement. 
Sand. 


Hours. 

Minutes 


Hours. 


Minutes. 


24 hours. 
7 days. 


00 
0^ 


7 days. 


28 days. 


1 



3 


23 
10 


[ 40 


2 


40 


441 .^28 


2,0.54.-5 

486.5 




1 


170 


219 












1 





All figures averages of five briquettes. 

Residue on No. 2!)0 sieve, 2 per cent; residue on No. 100 sieve, A per cent; residue on No. 50 
sieve, .3 per cent; specific gravity, 3.44: constancy of volume, good. 

Analysis— Lime, 50.33 per cent; silical, 27.20 per cent; aluminia. iron, 14.18 per cent; magne- 
sia, 3.22 per 6ent; sulphuric acid, 0.15 per cent; carbonic acid, 4.25 per cent. 



Washington University, 

St, Louis, Mo. , July 3, 1S9G. 

G-entlemen: Referring to yoar letter of May, I have examined and tested the 
small sample of cement sent me and I find the following results : 

fineness. 

95 x)er cent passes a No. 100 sieve. 
93 per cent passed a No. 130 sieve. 
These numbers give the number of holes per linear inch. 

soundness test. 

The soundness test was made by making up some balls of neat cement about 
1^ inches in diameter and leaving them to harden in a moist atmosphere for 
twenty-four hours, and then boiling them for five hours. This hastens the set- 
ting and will develop any inherent tendency to swell and crack after long ex- 
posure to the weather or to water from the slaking of a lime ingredient, or from 
other causes. It stood this test perfectly as there luas no tendency to crack. 

strength test. 

I could make but five briquettes, three of which were tested in seven days and 

two in twenty-eight days, having been left one day in moist air. The results of 

these tests are given on the accompanying certificate. 

Very truly, yours, 

J. B. Johnson, 

Professor of Civil Engineering. 
Illinois Steel Company, 

City. 

Note.— This certificate shows the tensile strength of the neat cement to be 429 pounds seven 
days and 448 pounds twentj^-eight days, one day in air, remainder in water. 



49 

Tests on Steel Portland cement made at mechanical laboratory, Tidane Univer- 
sity, Neiv Orleans, July 24., 18^7. 

TENSILE STRENGTH IN POUNDS PER SQUARE INCH. 



Neat. 


1 cement, 3 sand. 


Per cent 
water. 


Average for 
7 days. 


Average for 
28 days. 


Per cent 
water. 


Average for 1 Average for 
7 days. ! 28 days. 


19 


488 


549 


10 


211 286 



W. H. P. Creighton, 
Professor Mechanical Engineering. 



Tests on Steel Portland cement made by Clifford Richardson, New York, Sep- 
tember 25, 18^7. 



Proportion 
by volume. 


Per 

cent of 

water 

to 
weight 
of ce- 
ment. 


Initial setting 
time. 


Final setting 
time. 


* Tensile strength in 

pounds per square 

inch. 


Compressive 
strength in 
pounds per 

square inch. 


+3 

<D 

a 




T3 

02 


3 


03 

3 



W 


03 


;- 

C 




24 hours. 
7 days. 


28 days. 


^d 


CO 

CO 


1 
1 


25 

12 


1 


35 


2 


30 


264 


480 503 
145 ^00 


2,470 
933 


2,830 
938 





















*A11 figures averages of three briquettes. 

Residue on No. 200 sieve, 2 per cent; residue on No. 100 sieve, .4 per cent; residue on No. 50 
sieve, .2 per cent; volume constancy, good. 



Ransome & Smith, 

Concrete Specialists, 

Chicago, August 8, 1897. 

Dear Sir : Herewith results of the tests of Steel Portland cement. 

TENSILE STRENGTH PER SQUARE INCH. 
[Proportions by weight, cement 1, sand 3.] 





Age, 7 DAYS. 






Age, 1 MONTH. 




Maximum. 


Minimum. 


Average. 


Maximum. 


Minimum. 


Average. 


174 


170 


171 


265 




243 



50 

COMPRESSIVE STRENGTH IX TOXS PER SQUARE FOOT. 
[Proportions by -weight, cement 1, sand 3.] 





Age. 7 DAYS. 


Age. 1 MOXTH. 




Maximum. 


^Minimum. Average. 


Maximum. Minimum. 


Average. 


Hardened in -n-ater 

Hardened in air 


88 
88 


72 82 
64 81.7 


i 120 1 96 
112 1 108 


110 
110 







These compare favorably ^vith other brands of first-class cements. 

Tours, traly, 

Erxest L. Raxsome, 

President. 
Mr. J. Whitixg, 

Manager Cement and Brick Department, 

Illinois Steel Company, Chicago. 



Test of cement. 

Ixspector's Laboratory, 
Chicago Avexce Waterworks, 

Chicago, June SO, 1897. 

Steel cement from Illinois Steel Company, received 20th day of May, 1896, 
from department of public works, laboratory Xo. 185 & C. Condition of sample, 
fresh and in good order ; quantity, 100 pounds ; adduced weight per cubic inch, 
7,166 ounces; adduced weight per cubic foot, 77.4 pounds. Fineness passing 
2,500-mesh sieve, 97,74 per cent; fineness passing 10,000-mesh sieve, 97.09 per 
cent; time required to set, 110 minutes; heat evolved in setting, 7' F. in 70 min- 
utes. Soundness, i. e., freedom from checking, etc., sound; specific gravity, 2.8. 

TEXSILE STREXGTH. 



Description. 


Propor- 
tion. 


24 

hours. 


7 days. 


28 days. 


90 days. 


6 
months. 


12 
months. 


Steel cement 

Steel cement and approved 

sand 

Steel cement and inferior 

sand 


Neat....' 

1 1 
1 

3 


240 
46 
84 


359 
163 

107 


380 
226 

160 


431 
295 
191 


385 
336 
239 


539 

368 
2a5 



Conclusion, a good Portland cement ; approved. 

Remarks. — There are 400 pieces broken in all. A larger number would have 
given greater uniformity. With good sand the results show the average of Port- 
land cements. 

Sa:hl. M. Rowe, 

Inspector, City of Chicago. 
To Illixois Steel Company. 



W. S. MacHarg, Civil Engineer, 
The Rookery, 

Chicago, June 10, 1899. 

Dear Sir : Under your direction I have examined mortar and concrete made 
from "Steel Portland Cement" at the Donnelly Building, Polk and Plymouth, at 
the North Chicago Rolling Mills, and the Chicago Telephone Company's conduit 
at Chicago avenue and Wells street, all in Chicago. 



51 

These have been in place two and one-half to three and one -half years, and I find 
them in good condition with no sign of disintegration. I am also informed by 
the telephone superintendent of underground work that all their work done with 
this cement is equally good. 

So far, my examination is favorable to your cement. 

Very truly, yours, 

Wm. S. MacHarg, 

Consulting Engineer. 
Mr. Jasper Whiting, 

Illinois Steel Company, Chicago, III. 



W. S. MacHarg, Civil Engineer, 
The Rookery, 

Chicago, July 3, 1899. 

Dear Sir: In compliance with your request, I went to Shelby ville. 111., June 
15, in company with Mr. Bergquist. I examined about eight of the small piers 
out of the forty or fifty which were there, and also the pointing on a large pier. 
In all cases we found the concrete perfectly sound, with no sign of cracking or 
checking, and of very good quality. 

The thin plaster coat was apparently made very rich and there were some 

signs of slight air cracks in this coating, but no more than would be found in 

any other cement so treated. The examination was very satisfactory. 

Yours, very truly, 

Wm. S. MacHarg, 

Consulting Engineer. 
Mr. Jasper Whiting, 

Illinois Steel Company, Chicago, III. 



Statement of tests on Steel Portland cement made at laboratory, North Works, 

Illinois Steel Company, 1S97. 



d 
>> 


Sample tested. 


Fine- 
ness per 

cent 
on sieve. 


Initial set. 


Tensile strength in poimds per square 
after— 


inch 


u 
o 

i 


100 


200 


o 
W 


03 
f3 

ii 


1 

m 

0) 

o 
CQ 


o 




CO 


CO 


CO 

a 
o 

a 


T-H 


i 

04 


05 
CO 


1337 


Noat 




3.0 

7.3 
3.0 




50 

"""2(V 
45 
10 


187 
221 
405 
306 
210 
278 


431 
411 

*4(')lV 
484 
510 
243 
186 
141 
121 
330 
202 
156 
243 


520 
528 
560 
523 
()08 
438 
383 
320 
211 
21 It 
4()3 
265 
224 
864 


609 
603 
512 
521 
()51 
614 
513 
426 
2»1 
271 
556 
346 
301 
448 


785 
()45 
575 
(W) 
(599 
771 
.505 
4.58 
315 
320 
571 
39(5 
391 
428 


748 
648 
625 
.581 
795 
7:52 
57(5 
4(53 
312 
349 
578 
427 
425 
421 


678 
(550 
(598 
6:w 
763 
802 
514 
534 
3;J9 
371 
(52:1 
508 
4i»5 
573 


778 


1641) 


. ...do 


.2 


790 


431)1 


do 




5364 


do 




2.6 




5064 


do 




2.5 
1.4 




9284 


do 






1337 


1 cement to 2 simd. . . . 




571 


164H 


do 










605 


1327 


1 cement to 3 sand .... 










383 


164!) 


do 










402 


4261 


do 












6364 


do 












50G4 


do 












1)284 


do 



























(Correct) J. G. Beroqvist, 

Stipcriiifcndcuf. 



52 

DiCKMAN & Mackenzie, 
Chemists, Assayers, Metallurgists, and Mining Engineers. 

Analysis of Steel Portland cement. 

Silica 28. 95 

Alumina 11.40 

Lime 50. 29 

Magnesia 2. 96 

Sulphur ; ! . 1.37 

Iron oxide 54 

Alkalis .30 

Lost in ignition 3. 39 

DiCKMAN & Mackenzie. 



Chemical Laboratory, 
Tulane University, New Orleans, La. 

Analysis of Steel Portland cement. 

Silica 28. 40 

Alumina and iron 12. 80 

Lime < 51 . 50 

Sulphur as sulphides 1. 40 

Magnesia and loss not determined. 

L. W. Wilkinson. 
February 27, 1899. 



Appendix 3. 

Letter of i^resident of Illinois Steel Company to the Board. 

New Orleans, March 2 4., 1900. 

Gentlemen: A letter from Judge E. H. Gary, president of the 
Federal Steel Company, and a letter from Mr. Charles Mac Veagh, 
counsel for the Federal Steel Company and for the Illinois Steel 
Company, both addressed to the Honorable Secretary of War, were 
referred to you, and you were "requested to visit the Plaquemine 
lock and carefully examine the work done to date and the works of 
the Illinois Steel Company, where the details of the manufacture of 
Steel Portland, cement will be thoroughly investigated and the officials, 
of the company given a full opportunity to present their views rela- 
tive to the quality of their product and the proprietj^ of its use upon 
important engineering works." 

The investigation which you were requested to make having been 
now practically completed, it would seem proper for us to state, in 
brief form, some of the more important facts and conclusions which 
we have urged upon your attention, in the belief that they were such. 
as it was contemplated that the report which you were requested to 
make would deal with. 



53 

We believe that the following has appeared during the investigation : 

1. Tlie iron ores which are used by the Illinois Steel Company, 
coming, as they do, from the Lake Superior iron region, are remark- 
ably uniform in chemical composition, and free from elements, which, 
appearing in the slag, would be harmful to cement manufactured 
therefrom. 

2. The Illinois Steel Company purchases and uses in those of its 
furnaces producing the slag, afterwards manufactured into cement, 
only the purest and most uniform limestone available. In its efforts 
to get the best possible limestone, in view of its intention to use the 
slag for cement purposes, the company has lately purchased a lime- 
stone quarry. The limestone in this quarry has been caref ullj" tested 
and analyzed and found to be a perfect material for the purposes 
mentioned. 

3. The Illinois Steel Company has seventeen blast furnaces; it 
uses the slag produced from only two of these furnaces for the 
purx^ose of manufacturing cement. It is able therefore to select for 
use in these two furnaces those iron ores and limestones which will 
produce a proper and uniform slag, and to reject any that might be 
imx^roper in any respect for cement purposes. 

4. In practice, the cement department furnishes to the furnace 
department a set of specifications defining the quality of the slag 
which it will accept. If any slag is produced at these furnaces which 
does not fall within these specifications, it is rejected at once. This 
is determined by chemical analysis and phj^sical examination. We 
exhibited to j^ou daily reports from the furnaces, showing tliat when 
any of the slag fails to meet the requirements of the specifications 
it is at once rejected, and only that which is proper for cement pur- 
poses is shipped to cement works. 

5. Each lot of slag is again analyzed chemically, and inspected 
physically at the cement works, before it is used for cement purposes. 
Not only is this examination made, but a sample of cement is actually 
made from the slag and tested. The amount of lime which is added 
is determined from the analysis and tlie experiments above referred 
to. The amount required is about 10 per cent. 

G. One of the greatest difficulties with all cements lieretofore made 
from slag was tlie impossibility of securing a cement uniform in 
character. ]>y the means above mentioned it is evident that it is ])rac- 
ticable for the Illinois Steel Company to produce a cement absolutely 
uniform in ciiaraeter, and in that regard superior to any other cement 
whether made from slag or fi-om any other sul)stanee. We lia\(' fur- 
nished to^ou a large number of analyses made of oui- finished cement, 
fi-om time to time, which prove that the finishi'd cement manufae- 
tured by tlu' Illinois Steel Company is unifoi-m. 



54 

7. Chemical analyses show that our cement has practically the 
same chemical composition as other brands of Portland cement manu- 
factured by the older processes, except that our cement is somewhat 
lower in lime. It is evident that, if it were desirable, the amount of 
lime in our cement could be increased to correspond with the amount 
in other brands of cement ; but it has been found that by reason of 
the more perfect fusion of the materials on the blast furnace as com- 
pared to the cintering of the materials in the kilns of the older proc- 
esses the excess of lime commonly found in Portland cement is not 
necessary in our cement. This result is achieved by the chilling of 
the slag. The rapid chilling of the slag produces the same unbal- 
anced relation of the elements, one to the other, as is produced by the 
excess of lime in the clinker of the older processes. If more lime 
were added the excess would be injurious. 

8. Our cement is ground to a greater degree of fineness than any 
other cement in the market. At least 97 per cent of the finished 
product passes a sieve containing 40,000 meshes to the square inch. 
The result of this fineness is that a given amount of the material 
will carry a larger proportion of sand than other brands of cement. 

9. We broke in your presence a number of neat and sand bri- 
quettes taken at random from our laboratory. These show that the 
material possesses great strength and that the strength increases 
with age. We furnished you with a record of a large number of 
tests conducted over a period of three years. These records corre- 
sponded closely with the tests which we made in your presence. 

10. We also showed you samples of steam tests made on our cement 
and tests made with a view of ascertaining any possible expansion or 
contraction of the material. These tests, together with the tests of 
tensile strength, proved that the material is constant in volume as 
well as sound and stable. 

11. We also furnished you with a record of a large number of tests 
made to show the initial and final set of our material. This record 
is evidence that our material corresponds in this regard very closely 
to what is ordinarily expected of slow-setting Portland cement. 

12. We have shown to you a large amount of important foundation 
work in which our cement has been used. Some of these founda- 
tions have been built for more than five years. When cut into the 
cement in these foundations has proved to be tough and hard, but 
not brittle. The result is a foundation which is especially strong 
and which is not liable to swell or crack. We refer especially to the 
very severe tests of our cement shown in the excellent condition of 
the foundations of the rolling mill engine in our new slabbing mill 
at South Chicago. 



00 

13. We have also shown to you several examples of work in which 
our cement has been used where the surface of the work has been 
exposed to the air without moisture, notably the bridge abutment at 
Burlington and the experimental tank in the works of the Illinois 
Steel Company. The bridge abutment was built in 1896 and the 
tank was built in 1897. The wall of the tank was onl}^ about four 
inches in thickness and has been exposed to the action of the air and 
sun on both sides from the time it was built to the present time. 
The abutment was strong and hard in all points where good work- 
manship was shown. The tank was strong and hard throughout. 

14. A severe and thorough examination was made by you of the 
work already done upon the locks at Plaquemine. The cement in 
place was thoroughly homogeneous and was strong and especially 
tough. It is respectfully urged that for the mass of concrete in the 
Plaquemine locks and for other works of a similar character our 
cement is equal or superior to any cement known. The mass and 
the horizontal surface of the concrete at Plaquemine are entirely 
satisfactorj^ The vertical surface is not satisfactory and is very 
different from the surface of any other works of similar character 
which have been examined, and in which our cement was used. It 
is evident that the use of the cement on the vertical surface must 
have been attended by some exceptional circumstances which have 
not attended the other works. Just what these circumstances are, 
has not appeared. 

15. We have called our material Steel Portland cement. We have 
used the word "Portland" because we understand that term to refer 
to cements of a high grade, and because we believe our cement in its 
efficiency for heavy concrete and masonry construction is fully equal 
to the well-known brands of cement which are known as Portland 
cements. If it can be said that our cement is not a Portland cement, 
it must be because it does not fall within the definition of Portlaud 
cement as given in certain authorities upon the subject. The deli- 
nition to which we refer defines a Porthind cement as being one 
manufactured by the mixture of clay with lime-bearing materials, 
wliicli are then burned to a clinker and tlien ground to a powdiM-. 
In otlier words, the definition refers to the metliod of manufacture 
inst(iad of tin^ result as determining wliether or not a cement is a. 
I*()i'tlcUid cement. In the manufacture of our cement the clay anil 
more than 80 per cent of the total amount of lime containtnl in 
the finished cement are melted together in the hUist furnace ami 
then granulated by water. So far, this process corresponds with the 
process mentioned in the delinition refei red lo, e\ce[)t the eoini)hMe 
fusion and su<l<len ('hilling. Th(» addit ioii.il liini* neoi^ssary to the 



6(5 

efficiency' of the cement is then added and the mixture ground to- 
gether. The addition of this small amount of lime, after the burning, 
is the real difference. The distinction is well illustrated when we 
consider that if the granulated slag from the furnace and the neces- 
sary pulverized limestone were heated to a clinker,. and then the 
clinker ground to a powder, the resulting cement would clearly fall 
within the definitions of Portland cement to which we have referred. 
16. If our cement is not permitted in the works at Plaquemine, on 
the ground that it is not a Portland cement, it is because the method 
of its manufacture is not exactly the same as the method of the manu- 
facture of ordinary Portland cement, and not because it is not a 
high-grade and efficient cement suitable for work of this class. 
Yours, very resiDCctfuUy, 

E. J. BUFFINGTON, 

President Illinois Steel Company. 
Major AY. L. Marshall, 

Major WiLLLiM H. Bixby, 

Capt. Charles S. Riche, 

Corps of U. S. Engineers. 



Appendix 4. 

Tests of Tllinois Steel Company's cement made by the United States 

at Plaquemine, La. 

NEAT TESTS. 



Car received- 



Average neat tests. 



1 day. I 7 days. | 30 days. 



Car received- 



Average neat tests. 
1 day. 7 days. 30 days. 



July 6.1899 186 

July 12,1899 300 

Do.. ' 405 

July 17, 1899 332 

July 20. 1899 307 

Jul V 25. 1899 ! 259 

July 31. 1899 1 272 

Aug.2,J899 395 

Aug. 3.1899 275 

Aug. 8; 1899 270 

Aug. 11.1899 320 

Aug. u: 1899 197 

Aug. 2i; 1899 , 283 

Aug. 22.1899 213 

Do. 223 

Aug. 24,1899 231 ' 

Do 300 i 

Aug. 26.1899 ; 208', 

Do. 270' 

Aug. 31,1899 210: 

Do 241 ' 

Sept. 4, 1899 223 

Sept. 8. 1899 193 

Do 278 , 

Do 273 

Sept. 9, 1899 i 1.53 

Do 270 

Do 190 

Sept. 10. 1899 225 



460 
583 
597 
511 
487 
466 
425 
503 
5(30 
467 
552 
546 
540 
465 
390 
423 
425 
390 
400 
415 
515 
373 
418 
420 
543 
410 
435 
395 
463 



516 
591 
579 
596 
575 
525 
556 
475 
.537 
.524 
583 
624 
666 
610 
600 
610 
593 
512 
.502 
465 
540 
428 
494 
428 
485 
470 
435 
428 
440 



Sept. 16. 1899., 
Sept. 20, 1899., 
Sept. 19. 1^99., 
Oct. 4,1899..., 

Do 

Oct. 10.1899.., 
Oct. IL 1899.., 
Oct. 14. 1899.., 

Do 

Do 

Oct. 16,1899.., 

Do 

Do 

Oct. 19,1899... 
Oct. 20,1899.., 

Do 

Oct. 21,1899.., 
Oct. 23.1899.., 

Do 

Do 

Oct. 24.1899.., 
Oct. 26.1899.., 

Do. 

Do 

Do 

Do 

Oct. 28,1899., 
. Do 

Do 



275 

180 
295 
245 
330 
375 
285 
385 
242 
2&5 
312 
273 
342 
2;30 
310 
340 
278 
357 
330 
291 
405 
251 
260 
205 
359 
341 
282 
1.50 



392 
313 
503 
547 
517 
485 
532 
632 
507 
485 
480 
437 
540 
407 
486 
458 
472 
547 
635 
439 
437 
477 
365 

;^2 

372 

507 
302 
372 

384 



446 

448 
674 
544 
638 
500 
532 
468 
562 
554 
508 
502 
546 
498 
523 
544 
508 
558 
678 
574 
627 
586 
591 
483 
479 
548 
476 
478 
485 



57 



NEAT TESTS-Continued. 




SAND TESTS, BY VOLUME 1:3. 



Car received- 


Average sand tests. 


Car received- 


Average sand tests. 


7 days. 


30 days. 


60 days. 


7 days. 


30 days. 


60 days. 


Dec. .5.1899 

Dec. 7,1899 


262J 

166} 

157J 

148} 

148} 

148} 

183} 

1761 

1411 

153} 

140 

141} 

147J 

151} 

126} 

130 

178} 


387A 

270' 

221} 

213} 

212i 

212.1 

236} 

235 

211} 

238} 

212.', 

2061 

21 7 J 

236} 

213} 

207.1 

271} 


407i 

387i 

3511 

321} 

313} 

302.', 

3511 

3521 

337] 

277. i 

308 i 

330 

29(5} 

295 

2S8J 

2911 

311} 


Dec. 30,1899 

Do 


130 
146} 
128} 
153} 
148} 
145 
168} 
133} 
167^ 
211} 
226} 
138} 
(a) 
145 
147.< 
152.i 


196} 

203} 

227* 

208} 

198} 

216} 

243} 

206} 

227.V 

237.4 

2261 

228} 

130 

206} 

210 

196} 


283} 
272.4 


Do 


Jan. 2,1900 

1 Do 


297i- 


Dec. 8,1899 


286} 


Do 


Do 


285 


Do 


i Jan. 6,1900.- 

Do 


287i- 


Dec. 12,1899 


300" 


Do 


Do 


2874 


Dec. 13,1899 

Dec. 12,1899 


Jan. 8,1900 

Do 


2934 
347.4 


Dec. 14,1899 


1 Do 


298} 
303} 

(ft) 
(6) 


Do 

Dec. 17,1899 


Jan. 17,1900 

Jan. 25,1900 

Feb. 1,1900 

Do 


Do 


Dec. 19,1899 


(6) 


Do 


Do 


ib) 


Do 











a. Defective. b. Not broken. 

SAND TESTS, BY WEIGHT 1 :2. 



Car received- 


Average sand tests. 


Car received- 
Sept. 8. 189<) 

Sept. 19,1899 

Doc. 30,1899 


Average sand tests. 


80 days. 


60 days. 


90 days. 

36S 
412 
446 

1 


80 days. 

301 
303 

227i 


60 days. 

400 
362 

318S 


W) days. 


July 20,1899 

Aug. 8, 1899. 


821 
373 
330 


340 
405 
425 


480 
416 


Aug. 26,1899 


404 



58 
Appendix 5. 

International Conventions of Miinicli (188J:), Dresden (1886), Ber- 
lin (1890), and Vienna (1893), of delegates from Germany, Anstria- 
Hungary, Switzerland, Russia, France, America, Norway, Holland, 
Italy, and Spain, as to uniform methods for testing construction 
materials ; resolutions as adopted and as reported by J. Bauschinger, 
professor in the Munich Technical High School, and translated by 
O. M. Carter and E. A. Gieseler, and printed at U. S. Government 
Printing Office, 1896. 

Hydraulic Binding Media; Xomenclature, page 38. 

[Extracts.] 
NOMENCLATURE. 

1. Hydraulic limes are products obtained by the calcination of 
limestones containing more or less clay or silicic acid, and which, 
sprinkled with water, are slaked entirely or partially into powder. 
According to local circumstances, the lime is delivered in commerce 
in the form of lumps, or hydrated in the form of powder. 

2. Roman cements are products obtained by the calcination, below 
the verge of ^'Itrification, of marl containing much clay. They do 
not slake when sprinkled with water and it is necessary to employ 
mechanical means to reduce them to powder. 

3. Portland cements are products obtained from the calcination 
up to the verge of vitrification, of natural marl or of artificial mix- 
tures of substances containing clay and lime. They are reduced to 
powder by grinding, and contain at least 1.7 parts, by weight, of 
lime for 1 part of the material which gives to the lime its hydraulic 
property. To regulate certain properties of technical importance, 
there may be added foreign material up to 2 per cent of the weight 
without this addition necessitating any change of name. 

4. Hydraulic admixtures are natural or artificial materials which 
generally do not harden under water when alone, but only when 
mixed with caustic limes. Such are pozzuolana, santorin earth, trass 
obtained from certain volcanic tufa, furnace slag, burnt clay, etc. 

5. Pozzuolana cements are products obtained by intimately mixing 
powdered hj'drates of lime with hydraulic mixtures, ground to the 
finest of dust. 

6. Mixed cements are products obtained by intimately mixing 
manufactured cements with suitable admixtures. Sucli binding- 
media should be formally designated as mixed cements, with an 
indication of the materials entering into their composition. 



59 

Appendix 6. 

BesoliUion and declaration of Cement Trade Section, London Cham- 
ber of Commerce, on cement admixtures. 

The London Chamber of Commerce — (Incorporated), 
BoTOLPH House, Eastcheap, 

London, E. C, 1st Fehruary, 1898. 

Cement Trade Section. 

cement admixtures. 

For the past three years investigations into this matter have been 
made by the Cement Trade Section of the Chamber. They instructed 
Messrs. Stanger & Blount, of Broadway, Westminster, to make ex- 
tensive experiments with mixtures of Kentish ragstone with Portland 
cement, and also obtained valuable evidence from Mr. D. B. Butler, 
Mr. Gilbert Redgrave, Mr. LT. K. Bamber, and Dr. Michaelis of 
Berlin, and others. 

Aftef full consideration the Section adopted the following — 

RESO LUTION. 

That Portland cement be defined as a mixture of two or more suitable materials 
intimately and artificially mixed in the requisite proportions, and afterwards 
properly calcined and ground, to which nothing has been added during or after 
calcination, excepting that an addition not exceeding 2 per cent of gypsum is 
permissible for the purpose of regulating the setting. 

That the following rale be adopted: 

That if any material whatever excepting 2 per cent of gypsum for the purpose 
of regulating the setting be added to the Portland cement clinker during or after 
calcination, the article so produced shall not be sold as Portland cement, but 
under some other distinctive name. 

That the members of the Cement Trade Section of the London Chamber of 
Commerce, together with all manufacturers of Portland cement in Great Britain 
and Ireland who are not members of that association, be invited to sign the fol- 
lowing declaration of conformity to the above rule in respect of all Portland 
cement made by them wherever manufactured. 

DECLARATION. 

We, the undersigned, hereby agree to conform to'and carry out the rule of the 
Cement Trade Section of the London Chamber of Commerce as set forth in a n^- 
port made by the Section and adopted at a meeting held on Monday, the 10th of 
May, 1897: 

That if any material whatever excepting an amount not excoedint>- 2 ])or cent 
of gypsum for the purpose of regnhitiiig the setting b(^ added to the l\>rtland 
cement clinker during or after calcination, the article so produced shall not be 
sold as Portland cement, but under some other distinctive name. 

And we further agree that if at any time any of th(» ])arties to this agreement 
shall by resolution of a majority of those present at a, nitM>ting of such ]);nti<'s 



GO 



^1 



duly and properly convened in accordance with the practice of the London 
Chamber of Commerce, such resolution having been duly and properly confirmed 
by a majority of those present at a subsequent meeting called at not less than 
fourteen days' notice, be found to have failed to conform to and carry out the 
said rule, then in such case his or their name or names shall be struck off the list 
and notice of the same made public in such manner as shall be resolved. 

The above resolution was based upon the evidence of various ex- 
perts which can not be better summed up than in the following con- 
clusions of Messrs. Stanger & Blount: • 

Ragstone is a natural form of calcium carbonate mixed with siliceous matter. 
It is an inert substance incapable of setting when gauged with water. 

Ragstone when mixed with Portland cement undergoes no chemical change 
and does not combine with cement either in the dry state or when the mixture 
is gauged with water. 

Mixtures of ragstone and cement have a specific gravity lower than that of 
unmixed cement, and indeed correspond closely in specific gra\dty with that 
calculated from the respective specific gra^dties of the two materials. The spe- 
cific gravity of normal ragstone may be taken as 2.70 and that of normal cement 
as 8.15, so that the difference between them is substantial. 

Save for minor effects caused by the slight slaking action of moisture cofiimonly 
present in ordinary ragstone, the part played by ragstone mixed with cement 
is purely mechanical. The product obtained from the two materials is merely a 
mechanical mixture and is in no sense a chemical combination. In our opinion 
such a mixture can not correctly be termed Portland cement. 

Gypsum added to cement for the purpose of regulating the setting time in 
quantities not exceeding 2 per cent of the weight of the cement has no deleteri- 
ous influence on the quality of the cement. 

With respect to other materials, Messrs. Stanger & Blount say that 
they are unable to give a general opinion as to their influence on 
cement when mixed with it, and that they would have to report sep- 
arately as to each after long and careful investigation, and thej^ 
exxjress a strong opinion, in conclusion, that whatever be the effects 
whether good or bad, of the admixture of anj^ material whatever with 
Portland cement clinker after calcination, the article so produced 
can not legitimately be termed Portland cement. Each of the other 
experts examined indorsed this view, and the Section approve and 
adopt it. 

At a meeting of the Society of Chemical Industry, held on the 1st 
November, 1897, a paper was read by Messrs. Stanger & Blount 
upon these subjects, when, after alluding to the investigations made 
for the Section as to ragstone, they make the following remarks, for 
the reproduction of which the Chamber is indebted to the courtesj^ 
of the Society and of Messrs. Stanger & Blount : 

Ragstone is not a cementitious substance, and its addition to cement is an 
adulteration. 



61 

Perfectly sound cement is weakened by the addition of ragstone. 

This weakening is not fully proportional to the percentage of ragstone added, 
because the latter acts as a fine filling material and fills up the interstices natu- 
rally present in set cement. 

Cement which is not perfectly sound may be temporarily improved by the addi- 
tion of ragstone. When the cement has become sound by aeration this improve- 
ment disappears. 

Many minor points were examined and determined in the course of the main 
investigation, but the most important results are embodied in the conclusions 
given above. 

Additions to cement other than ragstone. — One of these which particularly 
came within our purview in the course of our investigation for the London 
Chamber of Commerce is gypsum. Gypsum is largely used in Germany and to 
a considerable extent in this country, in quantities not exceeding 2 per cent, and 
usually smaller than this, in order to lengthen the setting time of the cement. 
Regarding cement as a chemically finished product in the state in which it comes 
trom the kilns, needing nothing but mechanical comminution to make it saleable, 
the addition of any substance to the finished clinker must be considered, in strict- 
ness, an adulteration. Thus gypsum becomes under this definition an adulterant. 
Nevertheless it is added for a distinct and useful purpose, and in quantities smaller 
than 2 per cent does not affect the cement injuriously, so far as our experiments 
indicate. 

The last and worst adulterant with which it is our puriDose to deal is blast- 
furnace slag. As far as our experience goes, this most objectionable addition to 
Portland cement is not employed on the Thames and Medway, but in certain 
other districts it is used in large quantities for the preparation of a grossly 
sophisticated product which is fraudulently sold as Portland cement. 

We must not be understood as condemning true slag cement made by mixing 
granulated blast-furnace slag with slaked lime and sold under its proper title. 
This material is a perfectly legitimate product and has its own uses ; no one can 
reasonably object to its utilization if it is not covertly substituted for Portland 
cement. But the addition of blast-furnace slag to Portland cement is another 
matter altogether. The general practice of the manufacturers who seek to 
increase their profits by the use of slag appears to be to add to the clinker, as it 
goes to the crushers, as much crude blast-furnace slag as they consider can be 
mixed with Portland cement without risk of detection by the ordinary consumer, 
who buys cement in quantities so small that the cost of its analysis is too great 
for him to pay. The quantity added may be as much as 30 or 40 per cent, and 
detection is not easy or even always possible for an unskilled observer. Apart 
from the fraudulent character of this addition, about which no doubt can well 
be entertained, there arises the question of its effect on the cement. And here it 
is necessary to make a small digression into the chemistry of the subject. 

After stating their objections to the use of slag from the chemical 
point of view, Messrs. Stanger Su Ulount coiieliule tlioir paper as 
follows : 

All matorials added to Portland cement after th(> clinker conies from the kilns 
are adulterants, with the exception of gypsum, which is a recognized additimi for 
a specific purpose in quantities not exceeding 13 per cent. Of the two adulterants 
which have been specially dealt with, viz, ragstone and blast-furnace slag, the 



G2 

latter is by far the more objectionable, and it should be condemned and rejected 
by makers and users alike. In this view we believe we are supported by the 
great majority of engineers and manufacturers. 

By order of the Cemeut Trade Section. 

Chaeles Charletox, 

Chairman of Section, 
(I. C. Johnson & Co., Ltd.) 

Leedham White, 
Chairman of Special Admixtures Committee, 
(J. B. White & Bros., Ltd.) 

William Porter, 
(Burham Brick, Lime and Cement Co., Ltd.) 

Publication Com m ittee 

Kexric B. Murray, 
Secretary London Chamber of Commerce. 



The following firms have signed the declaration : 

Arlesey Lime and Portland Cement Company, Ltd Arlesey, Beds. 

Ashby & Son, William, Ltd London. 

Barron & Co., F. C Do. 

Booth & Co., Ltd Do. 

Borstal Manor Cement Company, Ltd Borstal, Rochester. 

Burham Brick, Lime and Cement Company, Ltd London. 

Clitheroe Portland Cement Company, Ltd Clitheroe, Lanes. 

Dartford Portland Cement Company, Ltd .... London. 

Dix, G-reen & Co Saffron, Walden. 

Earle, Ltd., C. & T Hull. 

Formby's Cement Works Company, Ltd London. 

Francis & Co. , Ltd Do. 

Francis, Son & Co., Ltd., Chas Isle of Wight. 

Gibbs & Co. , Ltd London. 

Globe Portland Cement and Whiting Company, Ltd Do. 

Hilton, Anderson, Brookes & Co. , Ltd Do. 

Hooper & Co Southampton. 

Johnson & Co. , Ltd. , I. C London and New- 

castle-on-Tyne. 

Laurence & Wimble London. 

Lee, Son & Co., W Do. 

London Portland Cement Company, Ltd Do. 

McLean, Levett & Co. , Ltd Do. 

Martin, Earle & Co. , Ltd Do. 

New Rainham Portland Cement Company, Ltd Do. 

Pattrick & Son, John Dovercourt, Essex. 

Peters Bros London. 

Phoenix Portland Cement Company, Ltd Do. 



G3 

Ponsonby, Hon. Ashley Artillery Cement 

Works, London. 

Potter & Son, Addison Newcastle-on-Tyne. 

<^ueenborough Cement Company ( Jaffray & Castle) London. 

Bichardson, A. & W. T Do. 

Robins & Co., Ltd Do. 

Kugby & Newbold Cement Company, Ltd Rugby. 

Scott, Ltd. , Walter Newcastle-on-Tyne. 

Skelsey's Adamant Company, Ltd Hull. 

South Wales Portland Cement and Lime Company, Ltd. . . Penarth nr. Cardiff. 

Tingey & Son, W London. 

Tower Portland Cement Company, Ltd Do. 

Trechmann, Weekes & Co., Ltd. . London and West 

Hartlepool. 

Tunnel Portland Cement Company, Ltd London. 

West Kent Portland Cement Company, Ltd Do. 

Weston & Co Do. 

White & Bros., Ltd., J. B Do. 

Wouldham Cement Company Do. 



Copies of the report of the Section can be obtained at the offices of 
the London Chamber of Commerce, Botolph House, Eastcheap, Lon- 
don, E. C, at the nominal price of 10s. 6d. each; also copies of this 
circular at 3s. per 100. 



Appendix 7. , 

Extracts from " Ciments et Chaux HydrauUcjues,^^ Candlot. 

E. Candlot : As extracted and transl^-ted from his book on " Ciments 
et Chaux Ilydrauliques," 1891 edition: Slag Cements, pages 1T2 et 
seq. ; Effect of Addition of Soda or Potash, page 90 ; Deterioration 
of Mortars, pages 228 et seq. 

[Page 173.] 

Slag cement. — Of late years certain blast-furnace slags have been 
successfully used in making a slow-setting cement called slag cement 
or pu/7Aiolana cement. 

Tlie shig is mixed with certain quantity of slaked fat lime or hy- 
draulic lime. But to obtain a cement of any strength it is necessary 
that the slag used be suddenly cooled as it comes from the furnace. 

Slags wliicli are cooled slowly and fi'om vitreous masses, or (lioso 
whicli pulverize spontan(H)usly in air, are not suited to cement making. 

Wln^n the slag is jilted into the water as il ('(unes from the furnace 
it. is reduced to small grains looking like sand. Slag so treated is 
called granulated slag. 



04 



1 



Besides the granulation, it is also necessary that the slag shall be of 
a particular chemical composition. According to M. Tetmajer,who in 
18S7 published a very complete treatise on this matter, the slag must 
be basic. When the proportion of lime to silica is less than unity 
the slag can not be used. The proportion of silica to alumina should 
be from 0.45 to 0.50. 

According to M. Prost* the composition of slags generally used in 
making slag cements may be represented very nearly by the formula 
2Si02, ALO3, 3CaO; slags of formula 2SiOo, AI2O.3, 4CaO, also yield 
a good cement, but the}^ mnst be cooled very suddenly and imme- 
diately upon coming from Ihe blast furnace. 

There are comparatively^ few blast furnaces which make slag fit 
for cement of good quality. 

The granulated slag is porous and the grains retain considerable 
water. It must be completely dried and then reduced to fine powder 
in any ordinary mill. It is then mixed with the slaked and sifted 
lime ; the generally adopted proportion is from 30 to 40 parts of lime 
to 60 to vO parts of slag, but very different proportions may be used. 

In order to get a cement of considerable strength it is indispensable 
that the slag and lime be mixed intimatel}^ ; the apparatus best suited 
to this work is the ball pulverizer. This apparatus consists of a 
drum turning on an axis and containing cast-iron balls of different 
sizes (sometimes quartz pebbles are used instead of the balls). 
The mixture of granulated slag and lime is put into the drum, which 
is then tightly closed and.revolved for a longer or shorter time, after 
which it is emptied, filled again, etc.f Thus the cement is reduced 
to an extremely fine powder. The residue held by a sieve of 5,000 
meshes (32,000 to the square inch) rarely reaches 20 per cent. 

Apparently it makes no difference whether fat lime or hydraulic 
lime be used to mix with the slag. In any case the lime must be 
thoroughly slaked. 

PROPERTIES. 

Chemical composition. — The composition of slag cements may 
vary within rather wide limits. Such cements generally contain 
more alumina and less lime than Portland cements. Some sulphide 
of calcium is alwaj^s present, and it may exceed 3 per cent or even 
4 per cent. It is to this ingredient that slag cement owes the green- 
ish tint which it assumes when kept under water. Under sea water 
the tint becomes much more marked. When a briquette of slag 

*Note on the manufacture and properties of slag cements, by M. Prost, Engi- 
neer of Mines, etc. 

f There are other kinds of apparatus in which the charging and emptying may 
be done continuously. 



65 

cement which has been kept under sea water for some time is broken 
the mortar gives out a very marked odor of sulphureted hydrogen. 
The sulphide of calcium is slightly soluble in fresh water and more 
so in salt water. If a small quantity .of slag cement be stirred in 
sea water, and, after setting, the clear liquid be decanted and a few 
drops of hydrochloric acid be poured upon the cement, tlie charac- 
teristic odor of sulphureted hydrogen will be noticed at once. 

Density. — Slag cement is light; an even litre of the cement rarely 
weighs a kilogramme. Its specific gravity is between 2.7 and 2.8. 

Fineness. — This cement is generally very finely ground, the maxi- 
mum of residue being, on a sieve of 900 meshes, 4 per cent; on one 
of 5,000 meshes (32,000 to the square inch), 20 per cent. It will 
yield good results only when extremely fine. 

Setting. — The setting is generally very slow; neat cement in fresh 
water requires eight to ten hours, and sometimes much longer, for 
setting. If the cement is mixed with sand and tempered to ordinary 
working consistency, the set is still slower and the initial hardening 
takes place only after fifteen or twentj' hours. B}^ adding certain sub- 
stances to the slag cement the set may be hastened. Silica or alumi- 
nate of lime maj^ be used for this purpose, but their action seems 
not to be. permanent, and when the cement is kept in bags the set 
becomes slow again in a short time. 

Strength. — The following table* gives the result of tests of different 
samples of slag cement. These tests sliowthat the neat cement does 
not make a great strength; it is often greater for cement with tliree 
X3arts of sand; also mortars 1 to 1 and 1 to 2 differ but little from 
those mixed 1 to 3. We have noted the same in regard to lime. 

If the cement is mixed with more than three parts of sand the re- 
sults are relatively less satisfactory^ Tlie tests quoted were made 
upon mortar packed hard in the molds ; mortar tempered to ordinary 
working consistency is not nearly so hard. 

Slag cement does not show great compressive strength, (^speciall}' 
for neat cement or for mortar with a small prox)orti^n of sand. The 
ratio between tensile and compressive strength does not exceed or 7 
for 1 to 3 mortar or for neat cement, while witli Portland cement this 
I'atio often exceeds 10. 

Mortars of slag cement attain theii* maximum strengtli al llic (mkI 
of a few months. Neat cement shows greater strength when im- 
mersed in sea water than in fresh water, but after a vim'v sliort time 
the strength decreases notably, and the breaking stivngtii is but a 
few kilogrammes {\n\v centinu^ter square). 



* Follows at the ond, of tin's ehaptor; not iiiclndod lu-roin. 



66 

Slag cement gives good results only in water or wet places ; in dry 
air its strength is not very great. Plastering made with this cement 
cracks and is not dnrable. M. Tetmajer says in relation to the nse 
of slag cement exposed to the air : 

In open-air strnctures where tlie surface can not be kept moist for about a 
week, and where it is exposed to the action of the sun, it is not well to use slag 
cement. Slag cements rich in lime (40 to 50 per cent), after keeping several 
vears in air, may disintegrate on the sui-face and crumble to powder, in con- 
sequence of amount of cracking. 

The relatively slight strength of this cement, neat or mixed with 
small proportions of sand, prevents its successful use for pavements, 
and o-enerally for any works which require great strength to resist 
either wear or blows. 

As far as known, slag cement does not seem to resist the decompos- 
ing" action of sea water for any long time. Mortars of this cement, 
when sufBiciently permeable, are rapidly attacked by solution of sul- 
phate of magnesia at yf^ (6 per cent solution). 

The powdered cement can not be kept long in a damp place, for 
the lime absorbs carbonic acid rapidly and the energy of the cement 
is considerably diminished. 

The treatise of M. Tetmajer on slag cement closes with these words : 

In o-eneral, we have tiied to give as complete information as possible upon the 
nature, manufacUire, advantages, and disadvantages of slag cement, and espe- 
ciallv upon the experiments made with the Swiss slag cement. We have inten- 
tionallv avoided, as far as possible, compaiisons with the modem and universally 
known cements, because in our opinion, the comparatively new cement just 
described is not expected to supplant existing cements, and because we are not 
prepared to follow the example of certain investigators who examine an entire 
class of products for the pecuharities of one particular kind, and therefrom di-aw 
conclusions ''pro domo."* 

Extract from general remarks of JLf. Tetmajer on the subject of slag cements. 

Puzzuolana cements are products obtained by the intimate mixture of slaked 
lime, powdered, with finely-ground hydraulic rock. 

Mixtures of finely-ground hydraulic materials with slaked lime in powder may 
yield hydrauhc mortars which, according to the character of the ingi'edients, 
are capable of acquiring the technically important qualities of the highest grade 
cements. This kind of cement ought to be designated according to the name of 
the base used in making it ; that is, slag cement, trass cement, etc. 

Puzzuolana cements made in this way lose the gritty character of theh com- 
ponent parts and become soft and flour-like. 

The color of puzzuolana cements varies with the materials used as a base. 
They do not become heated by tempering and as a rule they set slowly. If made 
with care puzzuolana cements do not warp (or swell) ; on the contrary they are 
hable to crack. 



"An analysis of M. Tetmajer's researches upon slag cement was pubhshed in 
" Annales de la Construction,'' July, 1886, and in the "Journal du Ceramiste et 
du Chaufournier," 1887. 



• 67 

Slag cements, the only kind of puzziiolana cement now made, may be recom- 
mended for use in all works under water, or in wet places, when rapid completion 
is not required, and a high strength at the start is not necessary. Slag cements 
are as well adapted as trass mortars for concrete to be built in water. 

In the air they lose their strength by cracking (checking) and by evaporation 
of water of hydration from the lime. 

In general their use is not recommended for works exposed to the air or sub- 
ject to mechanical wear. 

The specific gravity of slag cements is, in most cases, under 2.8; their loss by 
calcination varies from 5 to 10 per cent. 

The normal strength of mortar composed of one part of slag cement to three- 
of standard sand, after twenty- eight days, ought to reach at least 16 kilogrammes 
per square centimetre tensile strength (227 pounds per square inch) and 140 kilo- 
grammes compressive strength (2,000 pounds per square inch). 

[Page 96.] 

Carbonate of soda or potash accelerates setting. 

All differences in time of setting of Portland cements are due to 
the aluminate of lime. When a cement has been exposed to air this 
salt is already nearly completely hj^drated. The set is then solely 
due to the hydration of the silicate of lime, which always takes place 
slowly whatever be the composition of the water with which it is 
gauged. 

When the water contains in solution carbonate of soda or of potash, 
the dissolution of the aluminate of lime takes place much more 
quickly than in pure water and the setting is accelerated. 

[Page 228, Chapter C] 
CAUSES OF DETERIORATION OF MORTARS. 

The deterioration of mortars may be due either to poor quality of 
cement or to action of external agencies. In the first case, disinte- 
gration is produced within the mortar itself, which in a short time 
becomes affected throughout. In the second case, the effect appears 
at certain points or onl}^ on the surface and increases slowlj^ ; it may 
stop altogether after a time. 

1. Free lime. — When disintegration of a hydraulic mass is due to 
the cement it is nearly alwa^^s occasioned b}" an excess of free lime 
unslaked. The slow slaking of this lime causes a swelling which 
nuiy be enough to destroy the coliesion of tlie mortar. 

"A very small proportion of free lime," sayiS M. Le Cliatelier, "is 
sufficient to wholly alter tlie quality of a cenuMit. I have shown 
al)Ove tliat th(^ addition of 1 per cent of uiti-ate of lime to a ^ood 
cenuiut will r(Mluce its strength by one-hall. 'Hiis cause of dctiM-io- 
ration seems to me to des(M-V(^ more attention than it gtMUM'ally r**- 
ceives. I am persun.d<Ml that, nine tinu's out of teu, it is tlu^ soh^ 



68 

cause of deterioraiiou of hydraulic mortars exposed To air or to fresh 
water. If it often escapes notice, it is because its action sometimes 
is not visible until several months after use. or long after the usual 
period of tests." 

Decomposition of mortars is sometimes also attributed to the pres- 
ence of strongly basic aluminate of lime (Expansifs of M. Bonnami) in 
the cement or lime. It is hardly probable that this salt causes swelling 
in the mortar. It is very quickly affected by water and as it exists 
in comparatively small C[uantity in ordinary hydraulic materials, its 
hydi'ation must always be accomplished before the setting. 

Free lime, sufficient to cause swelling in mortar, may exist in Port- 
land cements of poor quality in consequence of improper mixture. It 
occurs more or less in imperfectly slaked hydraulic lime. Quick- 
setting cement generally contains a certain x3roportion of it. but 
these cements are calcined at a not very high temperatui-e ; they are 
always left exposed to the air for several days before using them, 
and the free lime thtis becomes ciuickly hydrated and is no longer 
injurious. Natural cements which are slow or moderate in setting, 
and ciments de grappiers invariably contain free lime when they are 
fresh made and often in considerable quantities ; for this reason they 
are not fit for use until they have been stored for some time in bins. 
In these cements, which are calcined at a temperature higher than 
the quick-setting variety, the free lime slakes much more slowly and 
a long exposure to moist air is necessary to insure the completeness 
of the operation. 

'2. JIagnesian cements. — Magnesia produces the same effect as free 
lime. Attention has been drawn to this of late years by the number 
of accidents occurring in works where magnesian cements were used. 

Magnesian cements show excellent tests and make masonry which 
presents all the solidity which could be desired for several months 
or even years. But sooner or later swelling begins and with a force 
which nothing can resist. {See on this subject the note of M. M. 
Durand-Clare and Deborav, Annates des Fonts et Chaussees. June. 
1886.) 

Experiments made at TEcole des Fonts et Chatissees have clearly 
determined the action of magnesia in causing mortars to swell. 
Bars of 1-meter length made of magnesian cement elongated 26 mm. 
to the meter in three years. Boulogne cement mixed with '25 per 
cent calcined magnesia showed a lengthening of 31.86 mm. per meter 
in the same time. Mr. Dyckerhoft' has also made some very inter- 
esting experiments to determine the effect of magnesia in Portland 
cements. They fully confirm the results obtained at TEcole des 
Fonts et Chaussees. 



69 

In Germany, also, accidents have been shown due to the nse of 
niagnesian cements. It is now generally agreed that these products 
should be proscribed. In France, cements are not allowed to contain 
over 3 per cent of magnesia.* 

3. Sulphate of lime. — Sulphate of lime may under some conditions 
cause accidents in masonry. If structures are to stand in air or in 
fresh water the presence of small proportions of sulphate of lime is 
of no great consequence. But it is different for works along the salt 
water ; a proportion of 2 or 3 per cent only of sulphate of lime, added 
to a cement after calcination, is sufficient to cause rapid decomposi- 
tion of a mortar made with such cement. If the sulphate of lime 
existed in the hydraulic material before calcination the danger is not 
so great, provided the calcining was not at a YQvy high temperature. 

The effect of sulphate of lime upon mortar is due to its combination 
with the aluminate of lime ; the conditions under which this combi- 
nation occurs have been determined, as also the composition of the 
salt formed. 

Sulphate of lime exists in small amounts in Portland cements and 
in hydraulic limes. In quick-setting cements it sometimes reaches 
7 per cent; this amount of the sulphate, however, seems to have no 
bad effect. We may even add to such cements 4 or 5 per cent of 
plaster and the mortar immersed in salt water will show no trace of 
decomposition. The aluminate of lime, which is present in large 
quantity in these cements, becomes hydrated very quickly and its 
combination with the sulphate of lime takes place before or during 
the setting. If by au}^ means the rapid hydration of the aluminate 
is prevented, as by mixing with the cement a little powdered slaked 
lime, then an addition of even 1 per cent of sulphate of lime would 
be enough to make this mortar disintegrate rapidly. 

Sulphate of lime is especially dangerous when water with this salt 
in solution filters through the masonry. (See Revue du Genie, 
Nov. -Dec, 1887, article on the action of gypsum ujpon mortars, by 
Captain Dolot.) 



Appendix 8. 

Extracts from " Le Beton et Son EmjjJol,^^ 31ahiels. 

Mahiels: As extracted and franslat(Ml liom his book on "Le l>eton 
et Son Emploi," 1S93 edition: I'oi'tland ('(Mnent niannracluin* ami 
sulphate oC lime admixtures, page lO; slag ('(Mnenls, pages ;>0 cf scif. 



* Magnesia is injurious only in cements which iiro cjiUinod iit a high tempera- 
ture; in those calcined at a low heat, such as Roman cements, magiiosia is not 
injurious. 



70 

[Page 30, par. 3.] 
• SLAG CEMENTS. 
Principle of fabrication. 

Some slags, pulverized, with a mixture of slaked lime give an ex- 
cellent cement. 

^N'ot every slag will suit ; it ought to present a definite composition ; 
it must be basic, that is to saj^ it must have a certain excess of lime. 

Scientifically, the equivalent of silica regarded as acid should be 
less than the equivalent of alumina and lime considered as bases. 

Xeutral and acid slags are unfit for the production of cement. 

Upon issue from the furnace the slag must be reduced to powder; 
it is granulated by the action of a jet of ver}" cold water. 

The granulated product has the aspect of coarse salt; it possesses 
the more energ}', the colder and more powerful the jet of water, and 
the hotter the slag. 

The granulated material is subjected to a drying process in order 
to expel dampness which it contains ; then it is broken and pulver- 
ized in mills and then mixed with lime. The quantity of lime added 
is variable ; it depends on the nature of the slag ; it varies between 
15 and 30 per cent. 

It is not necessar}^ that the lime be hydraulic ; common lime will do. 

H« ^ H^ ^ ^ H< Ht 

The mixture of the two powders is submitted to a new milling, which 
grinds any grains still existing. 

. The close union of the materials is completed in cylindrical appa- 
ratus, called " homogenisateurs," inclosing balls of cast iron rotating 
very rapidly. 

QUALITIES. 

1. Slag cement gives very great resistance, which rivals the best 
of Portland cement. 

Official tests made in 1886 in Germany showed resistances of 27 to 
28 kilogrammes for mortar 1 :3 at end of twenty-eight days. 

^ Hi Hi H< 4^ ^ ^ 

We will not fatigue the reader with a lot of figures; it is sufficient 
to say that for all practical purposes slag mortars give a safe resist- 
ance equivalent to that of Portland cement. 

2. The cement can be put in the work immediately after manu- 
facture. Its nature indicates that it can not contain quicklime, the 
swelling of which would cause cracking of the mass. 

3. The specific gravity is about 2.75. 

The density per litre, weight of powder, varies from 0.900 to 1 
kilogramme. 



71 . 

This weak density is a quality because the weight of slag cement 
assures a very much larger volume of mortar than does its equiva- 
lent quantity of Portland. Tliis quality is especially characteristic 
when impermeable mortars are in question. 

There is also an advantage in transportation charges. 

4. Slag cement is remunerative ; it costs about 30 per cent less than 
Portland. 

5. It succeeds especially' in works in fresh water; its finene^ss 
guarantees great strength combined with great impermeability. 

DEFECTS. 

1. The setting is somewhat slow ; it does not set until after eight to 
twelve hours. In certain works, rapidily carried on, this slow setting 
is an inconvenience. On the other hand it is an advantage, for it 
permits work and handling of great masses mixed for some time in 
advance. 

2. In air slag cement is less stable than Portland ; it cracks more. 
This cracking takes place while hardening ; this exacts a constant 
dampness. The theory of cracking, quite complex, has been studied 
by M. Tetmajer. 

One could to a certain extent obviate the evil by frequently water- 
ing the new work for two weeks. This sympathy of slag cement with 
water explains also its success in wet and submerged places. 

3. It appears susceptible to frost action; it can not be employed 
in open air during frost. 

4. It is attacked by salt water. 

Certain engineers of maritime works have declared a very great 
inalterability, but the experience has been for on\y one year. 

Numerous English engineers are of the opinion that concrete of 
slag cement resists salt water very well and that it acts equally as 
well above and below water level. They cite, for example, a jettj' 
260 meters long, built at Skinningrove, upon the most exposed 
coast of North Yorkshire, which has withstood for many years the 
attacks of the sea without presenting anj^ sign of deterioration. Tlio 
emergent face only appears altered to a depth of O.O'l meters; this 
alteration is hardlj^ visil)l(\ 

[Pago If,.] 
PORTLAND CEMENT. 

T*oi'Maii<l ceinenls are i)r()(lucts of very liigli buiMiing. 
U'iie (iegi*e(M)f biiniing ('()rresj)()iids to a tcmperalui'c of wliiti' licat, 
varying ])elw(»eii l,(i()() and 1,800 degrees. 

The calcareous niixlurc contains bnt 20 to "l') \)vv c-eiit of clay. 



n 

Portland requires a great accuracy of chemical composition. Lime- 
stone is seldom found in nature capable of furnishing the desired 
product. T\^henever such limestone is found it must be used with 
care because its composition is not constant ; one sample may vary 
from another. 

Artificial manufacture is therefore adopted. It consists in treating 
a mixture of limestone and clay, the ^proportions of which are regu- 
lated at will. For this reason the name ' ' Artificial Cements " is some- 
times applied to Portland. 

The principal materials, carbonate of lime and clay, are crushed, 
then intimately mixed with water. The paste thus formed is dried 
and passed into kilns, which are constructed on various systems. 
TThen the product comes out of the kiln it is examined and under- 
burned and over-burned pieces" are thrown out. The selected rock 
considered of good quality is broken into jDieces, reduced to powder, 

sifted, and stored. 

^ ^ ^ ^ 4: Hi H< 

[Page 19.] 
SULPHATE OF LIME (iX CEMEXTS). 

A minimum percentage of sulphate of lime is often specified in 
contracts. This minimum varies from 1 per cent to 1.5 per cent. 
Sulphate of lime is nothing else than plaster of paris. This tem- 
pered with water possesses the property of swelling. Its presence 
endangers the cohesion of cement mortars because the swelling, or 
rather the increase in bulk of this sulphate of lime, cracks and dis- 
locates the monolith. In submerged masonry construction this is 
serious and the danger is increased ; little by little the plaster which 
has destroyed the unity of the solid mass is either dissolved or carried 
away by the water ; voids form ; the mortar ha^'ing become permeable 
no more obstructs the circulation of water which washes out the 
interior of the construction. The danger is still more threatening 
in maritime works where all permeable mortar is doomed to early 
ruin ; the destruction caused by the washing out is increased by 
chemical actions which change the nature of the mortar even in the 
middle of the solid mass. 



Appexdix 9. 



Extract from ''Fabrication et Controle des Cliaux Hydrauliques et 

des Ci'tnents," Bonnami. 

H. Bonnami : As extracted and translated from page 98 of his book 
on • ' Fabrication et Controle des Chaux Hydrauliques et des Ciments," 
1888 edition, Paris : Checking of slag cements. 



73 

[Extract.] 

From information and experiment we iind that it is not nnder 
water, but in air only, that checlcing (or cracking) occurs in slag 
cements mixed neat. The drier the atmosphere the more free the 
checking. It seldom occurs when the air is saturated with moisture, 
and under water no change in volume takes place. 

The loss in fire test is sensibly greater for slag cements than for 
others. If the cement has not been exposed to the air and the added 
lime was thoroughly burned, the loss must be the escaped water of 
hydration from the lime. 

Theor}^ would indicate that slag cements ought to take a set in 
boiling water — an Induction confirmed by experience. 



Appendix 10. 

Extracts frorii "^ Manual of Lime and Cements,''^ Heath. 

A. H. Heath, of Royal Indian Engineering College: In the 1893 
edition of his book on Lime and Cement: Mechanical Mixtures, §13; 
Portland Cement, definition, §33; Adulterations, §89; Chemical An- 
alj^sis, §95; Proportion of Ingredients, §52; Slag Cement, §26. 

[Extracts.] 

* * mixture of pozzolana, etc., and caustic lime, * * * 

The chemical action induced by the mere mechanical admixture of 
these silicates is probably imperfect when the process of calcining 
the mixture is omitted. There is always a certain amount of risk 
attending the use of a mechanical mixture, due to the possibility of 
imperfect subsequent combination ; the mixing must be perfect and 
the ingredients must be in an extremely fine state of division to secure 
good results. In many instances it may prove to be a good method 
to mix powdered quicklime with the silicate of alumina, or siliceous 
volcanic ash, and to calcine the compound. Tlie lime then undergoes 
a second calcination in contact with the silicate and the cliemical 
combination during hydration takes place under favorable conditions. 
******* 

PORTLAND CEMENT. 

§33. Tlie most trustworthy, strongest, and most useful (HMutMiting 
material is produced mainly by calcining an ai'lificinl niixturiM)!* 
carbonate of lime and clay. It is called Porllnnd ('(muimU, * * * 

Of lat(^ years all the best cements an^ iiindc Ifoin an aiiilicial nii\- 
tui'e of natni-al snhslanccs conlaining known i)i'()p()rl ions of the 



74 

requisite ingredients for cement. As a general statement, a good 
mixture for cement will contain from T-2 to TT per cent of calcium 
carbonate and from "28 to 23 per cent of clayey matter. ^ ^ ^ 
The average chemical com|30sition of the cement is given by the 
following range of analyses ; also an average sample of a good cement 
made on the banks of the Thames : 





About. 


Avei 


-age. i 




About. 


Average. 


Lime 


58 to6t5 

21) to 26 

2. 5 to 10 

1 to 3 

to 2 
to 3 
2. 5 to 4 




61.5 

22.5 

8 

1.5 

9 

2.5 


Carbonic acid 

Phosphoric acid 

• Sulphuric acid 

Water 


... 1 to 3 
1 

... 1 to 2 
1 





Silica 

Alumina 

Potash 

Soda 

Alagnesia 


0.5 
1.5 



100 


Iron oxide 









It is therefore mainly composed of lime with silica, alumina, iron 
oxide, and some alkalis. "•' '^ * 

^ 4: ^ H: H( H< H< 

PROPORTIOX OF IXGREDIEXTS OF PORTLAND CEMENT. 

§52. An essential point in cement making is that the ingredients 
be in as fineh' divided particles as possible and in suitable proi)or- 
tions. One proportion is stated to be that the lime must not exceed 
three times the silica and alumina, nor be less than 2.5 times the silica. 
The following are said to be suitable proportions for good cement : 
Lime about 2 to 2.5 times the silica and alumina, and lime about 2.8 
to 3.75 times the silica. It is stated that a cement containing 65 per 
cent of lime and 35 per cent of silica set hard when used as a mortar, 
but finalh" broke up and fell into a white powder. On the other 
Iiand, a cement containing 70.7 x^er cent of lime and 29.3 of silica 
made a mortar which set hard and did not break up. IMr. Carej^ gives 
as good approximate X-)i*opoi'tions, 6 of lime to 2 of silica and 1 of 
alumina. ^ ^ ^ 

H« ***** * 

ADULTERATION OF CEMENT. 

§89. Cements are sometimes adulterated by the admixture of blast- 
furnace slag with the broken clinker before grinding ; also furnace - 
hearth scoria. Sometimes light-colored over-clayed or under-burned 
cement powder is darkened bj' the addition of lampblack or similar 
substance. The slag addition gives a greenish tint and also greater 
density, the appearance of high burning. The German Union of 
Cement Makers decided that all mixtures of solid substances with 
Portland cement were to be regarded as adulterations, an exception 
I)eino- made in favor of the addition of not more than 2 per cent of 



75 

plaster of paris, which is considered to improve the cement. It is 
on the whole advisable to consider every addition to the pure cement 
as an adulteration; the engineer using the cement can, if he wishes, 
add plaster of paris, but there is risk of lessening the durability of 
the cement by the addition of sulphates. 

H« ***** * 

Slag adulteration is neutralized to some extent if there be an ex- 
cess of lime in the cement powder. 



TESTS. 

§95. Chemical analysis. — A chemical analysis of a cement powder 
can not be depended upon as evidence of its quality as a cementing 
substance, inasmuch as the analysis.usually furnished does not distin- 
guish between a badly mixed and an imperfectly chemicallj^ combined 
cement and one that has been properlj^ made in every stage of the 
process, and, above all, it does not show whether the cement clinker 
has been well or ill burned. 

BLAST-FURNACE SLAG CEMENT. 

§2G. In the iron-making districts the slag or cinder from the blast 
furnaces, an aluminous calcium silicate, is sometimes used in the 
production of cement. 

The slag must be carefully selected to contain the proper propor- 
tion of silica, alumina, and lime. As it runs in a molten state from 
the furnace it is led into water, or on to a mechanical spreader work- 
ing above water, or is allowed to flow in a small stream downwards 
in front of a nozzle from which issues a jet of air or steam. It is 
tluis reduced to light frothy vesicular lumps, sand or dust, or to a 
fibrous state; the latter, called slag wool, is preferred at tlie Sivin- 
ningrove Ironworks, in the Cleveland district. The slag is tlien 
crushed or ground to a fine powder and is carefully screened. 

Then a quantity of pure slaked lime, in the foi'm of a (ine dry 
powder (from chalk or an}- pure limestone, calcined, crushed, slaked 
to powdei', and sifted) is added to the ground slag, and the two are 
intimately mixed l)y grinding to a very fine state of division, and are 
again screened. Tiie sieve test for final grinding is a residue not 
exceeding 25 per cent on a l52.00()-mesh sieve; usually tlie residue is 
15 per cent. The pi'()[)()i-li()ns ol" slag j)()\v(ler and lime \ai-y aeeoi-d- 
ing 1() tlie composition of the slag and ai"e measured by W(Mglil. 
Calcination of tlu3 mixture before the liiial gi-iiiding is nol ad(»|)i(Ml 
and is nol e\])eete(l to be a<lvanlage()us. 



76 



^ 



The slag used at Skinningrove is a double silicate of lime and 
alumina containing about 30 to 32 per cent of silica, 30 to 33 of lime, 
and about 25 to 28 per cent of alumina. The proportions of lime 
and slag vary according to the composition of the slag, the total lime 
in the cement being usually from 45 to 50 per cent. 



The resultant cement powder has an average percentage composi- 
tion, lime 45 to 47, silica 24 to 26, alumina and iron oxide 20 to 22; 
or lime 4.5 to silica 2.5 to alumina 2, the lime being about equal to 
the silica and alumina together. Comparing this with Portland 
cement, which is generally 59 to 61 of lime, 21 to 23 of silica, 7 to 11 
of alumina, etc., the excess of lime and alumina is noteworthy. The 
color of the cement powder is a grayish white. The weight of the 
cement is about 95 pounds per striked bushel. 

H< H« H* ♦ 4= H* H* 

Under tensile stress the resistance of mortar briquettes made of three 
of prepared sand to one of cement is, at twenty-eight days after mixing* 
(27 in water), 370 to 390 pounds per square inch on inch-section 
briquettes, increasing in five months to about 470 pounds. The 
limestone generally used at Skinningrove is procured from the mag- 
nesian limestone formation of Durliam, and comes from a bed beneath 
the magnesian stone ; it contains only about 1.5 per cent of magnesia 
and about 96 to 98 per cent of carbonate of lime. Fulwell, near 
Sunderland; Tuthill, near Hartlepool; and Raisby Hill, near Ferry- 
hill, are localities of some of the quarries. The tensile resistance of 
the mortar briquettes is found to follow closely the proportion of 
residue left on the 32,000-mesh sieve; the smaller the proportion 
the stronger is the cement. 

This slag cement has been used in the construction of a breakwater 
and pier about 850 feet long, on an exposed portion of the north 
Yorkshire coast, at Skinningrove Ironworks. The monolithic mass 
has up to the present time withstood all attacks of the sea and shows 
no signs of any deterioration. 

The cement is stated to be essentially hydraulic and not well 
adapted for work exposed to air and dryness, as it has been found 
that the skin of slag concrete so exposed is liable to become disinte- 
grated. It is a slow-setting cement and shows a tendency to con- 
tract during setting. At the Skinningrove pier the concrete below 
water level lias acquired a close, durable, hard surface, which resists 
attrition and also any decom]30sing action. Above water, after a 
lengthy exposure to air, the skin is said to become white and to be 
less satisfactory than Portland cement in a similar situation ; the 



77 

depth to which the skin is said to be affected is less than one inch. 
This alleged defect was not noticeable on a general inspection of the 
work. The color of the dry concrete is whiter than Portland cement 
concrete, owing to the light gray color of the slag used for the cement, 
and for making concrete. The concrete appears at present (1891) 
to be of excellent quality both above and below water. 



Appendix 11. 



Extract from ^'■Inspection of the Materials and Workmansliip Em- 
ployed in Construction,^'' Byrne. 

A. T. Bj^rne: In the 1899 edition of his Inspector's Pocket Book, 
Materials and Workmanship in Construction: Portland Cement, 
definition and characteristics, pp. 34-35; Slag Cement, pp. 42-43. 

[Extracts.] 
PORTLAND CEMENT. 

Portland cement is produced by burning with a heat of sufficient 
intensitj^ and duration to induce incipient vitrification certain argil- 
laceous limestones, or calcareous clays, or an artificial mixture of 
carbonate of lime and clay, and then reducing the burnt material to 
powder by grinding. Fully 95 per cent of the Portland cement pro- 
duced is artificial. The name is derived from the resemblance which 
hardened mortar made of it bears to a stone found in the Isle of 
Portland, off the soutli coast of England. 

The quality of Portland cement depends upon the quality of the 
raw materials, their proportion in the mixture, the degree to which 
the mixture is burnt, the fineness to which it is ground, and the con- 
stant and scientific supervision of all the details of manufacture. 

CHARACTERISTICS OF PORTLAND CEMENT. 

Specific gravity is between 3 and 3.05. As a rule the strength of 
Portland cement increases with its specific gravity. 

* * * .i« * si< :1c 

Adulteration. — Portland cement is adulterated with slag cenuMil and 
slaked lime. This adulteration may 1k^ dist iiiguislKMl by tju' light 
specific gravity of the cement and by the color, whicii is of .i inaiiNc 
tint in powder, wliile the inside of a water-pat wIkmi hroktMi is (hu^p 
indigo, (iypsum 01" snli)liate of linuMs also usimI as nn adnlter.int. 

* * * * :i! ^^< * 



78 

MISCELLANEOUS CEMENTS. 

Slag cements are those formed by an admixture of slaked lime 
with ground blast-furnace slag. The slag used has approximately 
the composition of an hydraulic cement, being composed mainly of 
silica and alumina, and lacking a i)roper proportion of lime to render 
It active as a cement. In preparing the cement the slag upon coming 
from the furnace is plunged into water and reduced to a spongy form 
from which it may be readih'' ground. This is dried and ground to a 
fine powder. The powdered slag and slaked lime are then mixed in 
proper proportions and ground together so as to ver}^ thoroughly dis- 
tribute them through the mixture. It is of the first importance in a 
slag cement that the slag be yqyx finel}^ ground and that the ingre- 
dients be very uniformly and intimately incoriDorated. 

Both the composition and methods of manufacture of slag cements 
vary considerabl}" in different places. The}' usually contain a higher 
percentage of alumina than Portland cements and the materials are 
in a different state of combination, as, being mixed after the burn- 
ing, the silicates and aluminates of lime formed during the burning 
of Portland cement can not exist in slag cement. 

^ H* 'i' ^ ^ 5H * 

Let Farge cement. — This is a patented cement similar to Portland, 
but, unlike Portland or the natural cements, does not stain marble, 
limestone, or other porous stones when used in setting them. For 
this reason it is largely used in setting and backing up the stonework 
in fine buildings. 



Appendix 12. 

Extracts from "^4 Treatise on Masonry Construction^'^ Baker. 

Ira O. Baker (professor, Universit}' of Illinois) : In the 1899 edition of 
his book on "Masonry Construction :" Portland Cement, paragraph 
71; Puzzolana, paragraph To; Slag Cement, paragraph 76; Cost, 
paragraph 78; Action of Sulphur, paragraphs 90-93. 

[Extracts.] 

71. Portland. — Portland cement is produced by calcining a mix- 
ture containing from 75 to 80 per cent of carbonate of lime and 20 
to 23 per cent of clay at such a high temperature that the silica and 
alumina of the clay combine with the lime of the limestone. 

As the quantity of uncombined lime is not sufficient to cause the 
mass to slake to a poAvder upon the addition of water, the cement 
must be reduced to a powder by grinding. 



79 

To secure a complete chemical combination of the cla}^ and the 
lime, it is necessary that the raw materials shall be reduced to a pow- 
der and be thorouglily mixed before burning, and also necessary 
that the calcination shall take place at a high temperature. Those 
are the distinguishing characteristics of Portland cement. 



75. Piizzaolana. — Puzzuolana is a term applied to a combination 
of silica and alumina which, when mixed with common lime and 
made into mortar, has the property of hardening under water. 
There are several classes of materials possessing this property. 
Puzzuolana proper is a material of volcanic origin and is the first 
substance known to possess the peculiar property of hydraulicity. 
* * * Vitruvius and Pliny both mention that puzzuolana was 
extensively used by the Romans before their day, and Vitruvius 
i^fives a formula for its use in monolithic masonrv which, with slight 
variations, has been followed in Italy ever since. . It is as follows : 
"Twelve parts puzzuolana, well pulverized ; six parts quartzose sand, 
well washed, and nine parts rich lime, well slaked." 



76. Slag cement. — Slag cement is by far tlie most important of the 
puzzuolana cements. It is the product obtained by mixing powdered 
slaked lime and finely pulverized blast-furnace slag. The amount 
of slag cement manufactured is very small as compared with Portland 
or natural cement, and apparently much more is manufactured in 
Europe than in America. Probably most of the so-called puzzuolana 
cements are slag cements. It is claimed that slag-cement mortar will 
not stain the stone laid with it. 



78. Cost. — * * * Slag cement is made in this country^ only 
at Chicago, where it sells at prices but little below those of similar 
grades of Portland cements. The imported puzzuolana sells sub- 
stantially the same as similar grades of Portland. 

^ iH :{: H< !i( Hi H^ 

90. The action of sulphur in a cement is extrcmel}' variable, d(^- 
I)ending upon the state in which it may exist and upon the nature 
of the cement. Snlphur may occur naturally in the cement or may 
be added in th<' loi-iii of suli)hate of lime (i)laster of p.iris) lo rctnrd 
the tinu^ of set. Under certain conditions the sulphnr may foi-ni sul- 
phidcis, which on exposure to tlie air oxidize and foriu sniphalcs .iiid 
canse tln^ moi'tar to (hM*rcasc in slrenuth. 



80 

Many, if not all, of the slag cements contain an excess of sulphides 
and are therefore unfit for use in the air, particularly a very dry 
atmosphere, although under water they may give satisfactorj^ results 
and compare favorably with Portland cement. 

♦ ♦ ♦ H« ^« :ic Hs 

93. A cement high in sulphides, as for example one made of blast- 
furnace slag, will successfully pass the above, the usual test for 
sounaness; and still the mortar when exposed in the air will show a 
marked decrease in strength and perhaps finally disintegrate. The 
presence of an excess of salphides may be suspected in any cement 
made from blast-furnace slag. 

A slag cement is indicated by a mauve or delicate lilac tint of the 
dry powder. 

55; sH H^ H< ^ ^ H* 

If there are any considerable indications of sulphides, before 
accepting the cement a chemical analysis should be made to deter- 
mine the sulphur and the prolDable ultimate action of the cement. 
Any cement containing sulphides in appreciable quantities is at least 
doubtful and should probably be rejected. Slag cements usually 
contain 1 to 1.5 XDer cent of sulphides. 



Appendix 13. 

Extract from ''Hydraulic Cement,''^ Spalding. 

F. P. Spalding (professor Cornell University) : In the 1898 edition 
of his book on "Hj^draulic Cement:" Hydraulic Index, Art. 3; Puz- 
zolana, Art. 9; Classification of Cement, Art. 10; Manufacture, Art. 
11; Slag Cements, Art. 14; Chemical Theory, Art. 20; Permanence, 
Art. 29 ; Sulphur, Art. 33 ; Tests, Art. 36 ; Chemical Analysis, Art. 63. 

[Extracts.] 

Art. 3. — hydraulic index. 

The hydraulic activitj^ of a lime or cement, that is, its ability to 
harden under water, depends primarily upon the relative proportions 
of the hydraulic ingredients and of lime. Silica and alumina are con- 
sidered to be the effective hydraulic ingredients, and it is common to 
designate the ratio of the sum of the weights of silica and alumina 
to that of lime in the material its hydraulic index. 

The hj^draulic index gives, therefore, within certain limits, a meas- 
ure of the hydraulicity of the various classes of limes. It is to be 
remembered, however, that there are other factors to be considered 
in judging of the action of a lime than this simple proportion. The 



81 

other ingredients may, bj^ their combinations, withdraw portions of 
the active elements so as to modify the effective ratio between them» 
while the activity of the lime depends largely upon the state of com- 
bination in which the active elements exist. This is not shown by 
analysis, and may be greatl}' modified by the manipulation given the 
material during manufacture. 

!jC ^ ^ ^* •!* •!* I* 

Art. 9. — puzzolana. 

The term puzzolana is commonly applied to a class of materials 
which, when made into a mortar with fat lime or feebl}^ hydraulic 
lime, impart to the lime hydraulic properties and cause the mortar 
to set under water. 

H< H< 4i ^ ^ ♦ H« 

Art. 10. — CLASSIFICATION OF CEMENT. 

:ic H« H« H- H« 4^ H* 

llie term Portland cement is commonly used to designate hydraulic 
cement formed by burning to the point of vitrifaction a mixture of 
limestone and clay in proper proportions and reducing the resulting 
mass to powder by grinding. ^ ^ ^ . n^y^Q high temperature 
emploj^ed in burning and the necessity of reducing the raw material, 
whether natural rock or artificial mixture, to powder before burning 
for the purpose of homogenizing it may be considered the distinctive 
characteristics of tliis class. 

The conference for the unification of methods for testing materials 

at Municli* propose the following additional definition of Portland 
cements: "They contain a minimum of 1.7 parts of lime per unit of 

hj^lraulic substances. The addition of 2 per cent by weight of for- 
eign matter may be tolerated in the manufacture of Portland cement, 
with the view of augmenting certain important qualities, without the 
necessity of changing the name." 

Sl(i(j cement^ or, as a more general term, puzzoJami cenient, is the 
product obtained by an intimate mixture of shiked lime witli iinelj^ 
I)ulverized puzzolanic material, commonly blast-furnace slag. In this 
material the hydraulic ingredients are not burned with tlie lime, but 
are present in the cement in a meclianical mixture only. 

#1% #(C •]> gjfi 7j^ 9|C ||C 

Art. U. — MANUFACTURE OF CEMENT. 

The manufacture of hydraulic cement as commonly practiced con- 
sists of foui' operations, viz, the preparation of th<^ raw material, 
the burning, the grinding, and the bolting. 

*Memoires do la Socioto des Ingrnieurs Clvils, 1801, vol. 1. p. 113. 




82 

The methods of preparing the raw material differ according to the 
nature of the material and the method to be used in burning. For 
natural cements it is usuallj' only necessary to select the proper por- 
tions of the rock and break it into fragments of suitable size for intro- 
duction into the furnace. The production of good cement requires 
the use of homogeneous material, and care must be used to prevent 
the introduction of variable rock into a single burning. 

For Portland cement there are three general methods of preparing 
the material, in all of which it is essential to good results that the 
various ingredients be very carefully iDroportioned and that they be 
formed into a very uniform and homogeneous mixture in order to 
facilitate the chemical changes in all parts of the material during 
the burning. The first, known as the wet method, consists in work- 
ing the raw materials into an intimate mixture by reducing to a paste 
with water, then drying into bricks, which may be stacked in the fur- 
nace for burning. In the wet process proper a large excess of water 
is employed and afterwards drawn off. In the semi wet process, now 
more commonly emploj^ed, only enough water is used to reduce the 
mixture to a plastic condition. 

The second method, called the dry method, consists in grinding 
the materials together dry or with a very small quantity of water, 
and making bricks of the ]30wder by subjecting it to iDressure in a 
brick machine. The bricks in all cases require thorough drying 
before being placed in the furnace. 

The third method is to grind the dry materials into powder and 
burn in a rotarj^ furnace without forming them into bricks, or to 
mix to a plastic condition and dry in small lumps on the circumfer- 
ence of a drjdng cylinder for burning in the rotary furnace. 

The exact proportioning of the ingredients and the intimacy of 
their incorporation into the mixture have ver}^ important bearing 
uiDon the value of the cement. 

The materials used in manufacturing cement differ greatlj^ in 
different localities and the method emx3loyed depends somewhat 
upon the character of the raw materials. For natural cements a 
limestone of high hydraulic index is usuallj^ employed, but differing 
nauch in composition, some having a high percentage of alumina, 
others of magnesia, and still others of both. For Portland cements 
the most common materials are a fat or slightly hydraulic limestone 
with clay or shale made into bricks by the semiwet process. Some- 
times a hydraulic limestone of high index (such as is used for natural 
cements) is mixed with a fat limestone, commonly by a dry method. 
These materials are also sometimes used by the method of double 
calcination, that is, the fat limestone is first burned in the ordinary 



83 

manner, the resulting quicklime is slaked and bolted, after which 
the slaked lime is mixed and ground with the argillaceous limestone, 
the object being to get a very perfect distribution of the lime through 
the mixture. 

The method of double calcination is also sometimes employed with 
rock containing naturally about the right proportions of hydraulic 
ingredients for making Portland cement. The composition of the 
rock being usually somewhat irregular, it is lightly burned and 
reduced to powder in order to secure greater uniformity and then 
formed into bricks and burned in the usual manner. 



Art. 14. — SLAG CEMENTS. 



The method employed in forming slag cement is to cool the slag 
suddenly by plunging it into a current of water as it emerges from 
the furnace. This makes the slag granular and causes it to retain 
the heat of crystallization, thus rendering its elements more ready 
to enter into combination in jpresence of water. 

Experience in Europe shows that the slag must be basic in order 
to be of use in making cement. Professor Tetmajer* arrives at the 
conclusion that slags in which the ratio of lime to the silica is unity 
are not suitable and that above this proportion the value of the prod- 
uct increases with this ratio. He also finds that the best results 
are obtained from slags giving a ratio Al2()3 = from 0.45 to O.oOSiOa. 

M. Prost f states tliat a considerable amount of sulphur may be 
unobjectionable in slag cements, and mentions a case where good 
results had been obtained with sulphurous slag, the only effect being- 
discoloration attributed to suljjhide of iron. He also concludes that 
a slag is most advantageous for this purj)ose which is most rich in 
lime and alumina. 

It is very important in slag cements that the slag be ground \evy 
fine and be very intimately mixed with the lime. The lime is slaked 
and bolted and then ground mechanically with the slag powder so as 
to insure thorough incorijoration into tlie mixture. 

In consequence of the necessity of obtaining extreme pulverization 
of the slag it is necessary to first dry it. Tlu^ water which serves to 
make it granular remains to some extent between the grains and 
makes bad lumps at time of grinding. It has been attempled to 
substitute quicklime for slaked lime and use this water for slaking, 



* Annates do la Construction, Juillot, 1880. 
I Amiales dos Minos, ISSO, vol. II, p. 158. 



84 

but iinsiiccessfnlly. the slag combiniiig to some extent with the lime 
and thus weakening the cement, while particles of quicklime being 
left in the cement cause swelling of the mortar after setting. The 
drying is done in a furnace at a dull red heat. 

The powdered slag is bolted through a fine sieve — about 10,000 
meshes per square inch — before mixing with the lime. 

The lime may advantageously be kept for some time after slaking 
before being used, as this insures the complete reduction of the 
quicklime, but the slag seems to deteriorate when kept long after 
grinding. Fat lime is commonly employed for this purpose, bnt 
there seems to be an advantage in using meagre lime on account of 
the mortar being less likely to crack when used in the air. M. Prost 
found that there was no advantage to the strength of the cement in 
using hydraulic lime. Various additions of puzzolanic or other 
material are also sometimes resorted to for the purpose of prevent- 
ing the cracking in air when fat lime is used. This also increases 
the activity of the cement. 

The composition of slag cement usually differs from that of Port- 
land in ha^'ing a less quantity of lime, more silica and alumina, and 
more alumina in proportion to the silica. 

Table IV gives the composition of a number of samples of the 
leading European slag cements, taken from Candlot and Tetmajer. 

Slag cement is usually slow setting, but the activity varies greatly 
with the circumstances of use. The rapidity of action is greater as 
the proportions of lime and alumina increase. 

Slag cement acts better under water than in the air. 

Table IV. — Composition of slag ctmtnts. 
Silica. Almnim. Iron oxide. Lime. Magrnesia. ^^^^P^^ Log.- i- ^'^i^^- 



1 

o 

3l' 


24. >:■ 

34.60 

24.90 

24.30 

27.45 

25.20 

2»3.4it 

is. 30 

23.35 

37.35 

31). a5 

18.69 , 

19.87 1 

18.11 , 

20.94 ! 

19.34 


19. lo 
13.46 
13.46 
13. S5 

14.65 
15.23 
IS. -59 
is 07 
12. .s3 

9.13 
14.05 

9.20 
14. 84 
15.54 
U..N5 
17.15 


2.67 
0.84 
2.83 
1.15 
1.75 
0.77 
0.41 
0.34 
0.64 
1.-50 
0.28 
2.14 
0.80 
0.92 
1.08 
1.07 


36.60 
50.23 
50.411 
49.50 
46.20 
50.00 
50.07 
53.16 
55.61 
50.38 
50.36 
46.36 
48.54 
54.73 
4>. IS 
54. 21 


6.76 
2.65 
1.2IJ 
3.16 
1.86 

La=> 1 

0.50 « 

0.64 

3.17 

5.73 

3.68 

4.92 

2.44 

0.54 

3..SS 

•'. -1 


2.10 
2. 70 
1.10 
LS6 
0. 72 
0.72 
0.08 
0.18 
0.27 
0. 40 
3.39 
L35 
l.iX' 
0.37 
1.69 
':■. :59 


7.50 
5.40 
6.45 ... 


0.44 
0.13 


o 
6 


6.90 . 
7.00 
6.50 
8.30 ... 


0.2S 
0.37 
0.23 


8 


8.07 ... 




5' 


4 01 !... 




10 
11 


3.59 ... 
6.99 i... 




13 


13.19 I... 




13 

14 ; 


8.41 1... 
8.64 ... 




\\^ 


7.*' ... 




16 


6. 39 ... 











It is essentially a hydraulic material, and it is especially important 
that it be kept damp during the early period of hardening, in order 
that the water necessary to its proper hardening may not evaporate. 



85 

Art. 20. — chemical theory. 

* * * Chemical analysis shows the proportions of the various 
elementary substances of which the cement is composed, but not 
their state of combination, and the action of a cement may be greatlj' 
modified by altering the condition in which the ingredients exist 
through changing the manipulation in manufacture without altering 
their relative quantities. 

jjc ^ ;i« 4! H* H* ^ 

Art. 29. — permanence of volume. 

il<: ^ ^ ^ ^ ^ ^ 

Sometimes cement when made into mortar sets and hardens prop- 
erly, and later, when exposed to the action of the atmosphere or 
water, becomes distorted and cracked, or even entirelj^ disintegrated. 
If the composition deviates but slightly from the normal this process 
of disintegration may not show itself for a considerable time, and 
proceeds very slowly. It thus becomes an element of considerable 
danger, as it is liable to escape detection in testing the cement. 

Art. 33. — sulphur compounds. 
The action of sulphur in cement is extremely variable, depending 
upon the state in which it may exist and the nature of the cement. 
The effect of adding sulphate of lime for the purpose of rendering 
the setting slower has already been discussed (Art. 21). This action 
depends upon the presence of aluminate of lime in sufficient quantity 
to take all of the sulphur into combination. When the sulphate is 
added in excess, or to a cement without the aluminate, it remains solu- 
ble in the mortar and is graduallj^ dissolved out, having onlj^ the 
tendency to make the mortar porous. 

*»Sf uS^ *if ■!• «^ ^» 

•T* 'T* "T* ^ 'T^ *^ 

Professor Tetmajer states that calcium sulphate in Portland cement 
sometimes acts as an expansive tlirough the fact that it is readilj^ 
oxidizable and expands in oxidation. 

In slag cements the presence of calcium sulphide is thouglit to be 
less injurious. According to M. Prost it gives a green color to the 
cement when kept in water, but without injury to its sti'ongth. In 
the air it may cause the mortar, to crack. 

>ii ^ :^ ^ ^ Ht mt 

Art. 3G. — object of tests. 

* * * What it is necessary to know ahoiil tlie (*(Muont is tliat it 
will set and linrdcMi inlo a solid mass, wliich will lirnily ndiicre to 
any surface willi wliicli it may be in contact, and tlnit it will ciuhnv 
through a lonii" lime williont change ol" loi-in or loss of solidilw 



86 

As ordinaiy tests must be made in a short time, but a few days at 
most being usually allowed for determining the quality of the mate- 
rial, the iDroblem to be met in testing is to apply such tests as will 
enable a prediction to be made, from its behavior under them in a 
short time, as to what it will do in a long time under the circum- 
stances of its use. The difficult}^ of this with a material varying so 
greatly in character and in its behavior under various conditions is 
evident. Having a particular brand of cement whose characteristics 
are known it may readily be determined whether a given sample is 
of normal quality, and something may be predicted of its future from 
its behavior under short-time tests. Yery little, however, can be 
done in the way of generalization, and for a new and unknown ma- 
terial it is only possible to state a somewhat indefinite probability as 
to final results. 

* * * Cement giving high early strength is to be relied upon 
only in so far as it has been shown by experience capable of subse- 
quently maintaining such strength. * h« * 

4: ^ ^ H: Hi H< H< 

Art. 63. — chemical analysis. 

Chemical analysis is of verj^ great value in the studj' of the 
prox)erties of various cements, and is commonly employed hy manu- 
facturers in regulating the quality of their products. It is not com- 
monly used for the purpose of determining the quality of a cement 
and is not of much value as a test for the reception of material. 

The quality of the cement depends not only upon the ingredients 
being properly proportioned, but also upon the state of combination 
of the ingredients, and this in turn depends upon the manipulation 
given the material in manufacture. Analysis shows the proportions 
of the various ingredients, but does not show their state of combina- 
tion. The results of an analysis may show that the composition is 
such that a good cement may be made from the ingredients, but 
other tests are necessary to show whether it has been made. h« * * 



Appendix 14. 

Extract froia '^Portland Cement,^^ Jameson. 
C. D. Jameson, professor Iowa State University: In the 1898 edition 
of his book on Portland cement: Definition, page v (iDreface) and 
page 94:. 

[Extracts.] 
PREFACE. 

The term "Portland cement" as here used means an artificial ce- 
ment made by mixing in certain known proportions, clay and chalk 



87 

containing silica, alumina, iron, and carbonate of lime, and burning 
this mixture to the point of incipient vitrifaction and then reducing 
this burned product to an impalpa;ble powder. 

sjc * Hi * * * * 

COMPOSITION AND CHARACTERISTICS OF PORTLAND CEMENT. 

Portland cement is a product formed by sintering* together mate- 
rials containing only clay and lime and finely pulverizing. It is 
allowable to add not more than 2 per cent of plaster of paris or of 
some similar substance for the purpose of rendering the setting of 
the cement slower. Beyond this, all additions or substitutions are to 
be regarded as ad niter ations.\ 

An ideal cement of this class should possess the following compo- 
sition : 

Per cent. 

Lime , 62 . 2 

SiHca 28. 2 

Alumina 9. 6 

100.0 

But up to about a third of the alumina may be replaced b}^ ferric 
oxide, which would correspond to the composition : 

Per cent. 

Lime 61.7 

Silica 27.4 

Alumina 7.5 

Ferric oxide 3.4 

The following table shows how nearly the actual Portland cements 
approach in composition the above ideal. The maxima and minima 
given are derived from analyses of nine representative English and 
German manufacturers. 





Maximum. 


Minimmn. 




Maximum. 


Minimum. 


Limo 


62 
2-t 

8.8 

5 

3.5 

1 


57 
19 

5.3 

2 

0.3 

0.4 


Soda 


0.8 

1 

3.9 

1.9 

1.5 


O.-t 


Silica 


Sulphuric acid 

Sand, etc 




Alumina 


1 


Ferric oxide 


Carbonic acid 

Water 





Magnesia 





Potash 











Portland cement should not have a lower specific gravity than 1^.00 
in the case of long-stored sami)les, nor lower than o. l'^ when freshly 
Ignited. The best ([ualities exhibit a density notably higher than 
this, viz, WAX to :>. 15. 



*That is, heating to the temperature of incipient fusion. 
f Definition adopted by the Association of German Portland Cement Mann 
factureis. 



88 

Appendix 15. 

Extract from ^^Proceedings of Institution of Civil Engineers,^'' 

England. 

J. Grosclaucle: From page 419, vol. 98 (1889) "Proceedings of Insti- 
tution of Ci^il Engineers," England ; as abridged and translated from 
page 89, ^vlj 21, 1889, Annales Industrielles. 

[Extract.] 

The manufacture of cement from slag has in the last few years 
become rapidly extended, and works are now in operation in France 
at Saulnes and Marnaval, in England at Middlesbrough, in Switzer- 
land at Choindez, at many places in German}^, and at Bilbao in 
Spain. The quality of the cement varies considerably in accordance 
with the composition of the raw products employed, and the care 
exercised in the manufacture, but the materialwhen well made will 
bear comparison with the best Portland cement. The slag emploj^ed 
should be basic, and must be pre^i-ouh^ granulated on the system of 
Mr. C. Wood, as otherwise it is devoid of hydraulic properties. 
According to Professor Tetmajer, of Zurich, the lime, silica, and 
alumina in the slag should bear to one another approximately the 
following proportions: As 46, 30, 16. Fat or pure limes are generally 
selected to add to the slag, but the author counsels the adoption of 
poor or clayey limes in cases where the cement is to be used above 
ground. Where much calcium sulphide is j)resent, as in Bilbao 
slags, the cement takes a greenish tinge, but this does not impair its 
quality. A sample tested by Professor Tetmajer, composed of 100 
parts of Bilbao slag and 15 parts of lime, was found on analysis to 
give the following percentage results: Silica 30.56, alumina 13.31, 
oxide of iron 0.25, oxide of manganese 1.74, oxide of lime 45.01, mag- 
nesia 2.96, sulphate of lime 1.41, and sulphide of calcium 4.63. 
Briquettes of the neat cement were tested as follows : 

Seven Twenty- 

days, eight days. 

Strength in compression per sciuare centimetre— Kilos. Kilos. 

In water ! 96. 9 ' 120. 9 

In air 144. 

Tensile strength per square centimetre — i 

In water i 19. 3 28 7 

In air 19. 5 

The mode of preparing the slaked lime and the apparatus used for 
the purpose is exiDlained b^^ reference to diagrams. Drawings are 
given of various descri]3tions of diying machines which have been 
employed for desiccating the granulated slag. The rotary drier, 
invented by Mr. Ruelle, is j)ref erred bj^the author, and a novel form 
of apparatus, patented hy Mr. Raty, of Saulnes, is described and 
fully illustrated. For the intimate admixture of the slag and slaked 



89 

lime, and for grindiag tli3 same to a fiue powder, the apparatus of 
Mr. Luther, of Brunswick, is emploj^ed. This consists of an iron 
cylinder with a corrugated lining partly filled with small metal 
balls, by means of which the materials are both ground and mixed 
in one operation, whicli lasts about three-quarters of an hour for 
each charge. The cement thus prepared leaves a residue of from 
5 to 6 per cent on a sieve of 2,500 meshes per square centimetre. A 
sample of slag cement made at the Donjeux factory was officially 
tested at the Ecole des Fonts et Chaussees in September, 18S8, with 
the following percentage results: Combined silica 23.85, alumina 
13.95, peroxide of iron 1.10, lime 51.40, magnesia 1.95, sulphuric 
acid 0.45, sand 0.25, loss on ignition 7.05. It left on a sieve of 
5,000 meshes per square centimetre a residue of 23 jjer cent; gauged 
with 28 per cent of water, the initial set took place in one and a quar- 
ter hours, and the set Avas complete at the end of three hours. On 
the mean of six tests the neat cement showed the following tensile 
strength x:>er square centimetre: In seven days 21.87 kilogrammes, in 
twenty-eight days 26.88 kilogrammes, and in eightj^-four days 31.15 
kilogrammes (equivalent per square inch to 311.06 pounds, 382.32 
pounds, and 443.05 pounds, respectively). Briquettes of 3 parts 
sand to 1 cement broke in seven days at 14.93 kilogrammes, in twentj^- 
eight daj^s at 26.03 kilogrammes, and in eightj^-four days at 29.23 kilo- 
grammes (equivalent x)er square inch to 212.35 pounds, 370.23 i^ounds, 
and 415.74 pounds, respectively). Tables too long for abstract indi- 
cate the composition of twenty-three different samx3les of slags from 
various foreign furnaces, together with tests of the cements made 
from the same. 

An estimate is given of the cost of the plant for a works capable of 
producing 6,000 tons of cement per annum, and of the necessarj^ 
materials for the same, also of tlie expense of manufacturing the 
cement and the profits on the manufacture. The estinuite is accom- 
l^anied by i)lans and sections of the factory. 



Appendix 16. 



Extracts from ^^ Proreedingsof Instlfiilion of Civil EiKjineers,''' Eng- 
land. 

G. R. Redgrave: In pages 215 etseg., vol. 10.") (1891), " rroceedings 
of Institution of Civil Knglneci's/' England: M.uuiracliirc and 
Properties of Slag Cement. 

[Extriicts.] 

Tii(^ i-(M'('nl discovery of llic possibilily of i)r()dni'ing a. hydraulic 
cemc^nt from a mixture of blast-furnace slag and slaked lime throws 
much light ni)()n certain facts connected with the indni'atioii t>f 



90 

cements, and in the present paper an account is given of this ma- 
terial and the results of the tests to which it has been submitted. 

Blast-furnace slag, though it varies greatly in composition in 
accordance with the nature of the ores emploj^ed in the smelting of 
iron, contains generally all the chief ingredients found in Portland- 
cement clinker, and on this account has often attracted the attention 
of cement makers. In this country attempts have been made by Mr. 
F. Ransome, Mr. Charles Wood, and Mr. John Watson, to turn this 
material to profitable account, but hitherto without much success. In 
Germany less scrupulous manufacturers have availed themselves of 
slag in the adulteration of cement, for which purpose its great simi- 
larity with the "core," or hard particles present in genuine cement, 
renders it peculiarly suitable, while its detection by chemical analy- 
sis is a matter of considerable difficulty. The many failures experi- 
enced by previous inventors, coupled with its use for fraudulent 
purposes, have given slag a bad name among those who are engaged 
in dealing with cements. 

The steps by which Messrs. Bosse and Wolters have succeeded in 
overcoming the difficulties encountered by previous inventors are 
based upon the careful consideration of the chemical composition of 
the slag, and of the processes best calculated to bring the cementi- 
tious properties into action. All slags are not equally well adapted 
for the manufacture of cement, and those slags which disintegrate 
and fall into powder spontaneously, and which on this account have 
been preferred for purposes of adulteration, are wholly unfitted for 
cement making. Again, all slags highlj^ charged with mineral oxides, 
compounds of sulphur, and large proportions of magnesia should at 
once be rejected. It is, however, easy to procure almost inexhaustible 
supplies of blast-furnace slag in which, while the percentage of lime 
in proportion to the silica and alumina is relatively high, it still falls 
far short of the amount of lime present in a good sample of Portland- 
cement clinker. Care must also be taken that the silica and alumina 
bear a certain fixed ratio to tlie lime. By selecting a slag of this 
composition, which has been specially j)repared by incorporating 
with it a sufficient quantity of lime to insure further chemical action 
and by bringing about an extremely intimate mechanical mixture of 
the ingredients, the inventors of the slag cement have produced a 
material resembling Portland cement in the extent and energy of its 
hydraulic action, and surpassing it in its sand capacity, or power of 
binding together the aggregates employed in the ]3reparation of mor- 
tar or concrete, as also in certain other respects. During their pre- 
liminary examination of upwards of one hundred varieties of slags, 
the inventors have encountered several peculiarities which are at 
present very difficult to explain, or to bring into accord witli existing 



91 

theories, and it is necessary, before any definite opinion can be pro- 
nounced respecting any given sample of slag, to submit it to a careful 
analysis and to repeated tests. 

^« Hs ^ ^ H< * * 

In its chemical composition the slag cement differs widely from 
Portland cement, mainly in the higher percentage of alumina present 
and in its relatively low percentage of lime, which, unless a larger 
proportion than is actuallj^ required has been added for some special 
purpose, need not exceed 45 to 50 per cent against from 58 to 62 per 
cent generally present in Portland cement. The following is the 
composition of a good sample of slag cement, and side by side with 
it, by way of comparison, are the quantities of the ingredients usually 
present in Portland cement. 



Ingredients. 



Slag 
cement. 


Portland. 


46. .>} 


60. .59 


2-t.lO 


22.23 


16.30 


7.22 


0.93 


4.32 


2.08 


1.10 


0.65 


0.80 


6.4.5 


1.05 


2.05 


1.68 


0.94 


1.01 


100.03 


100.00 



Lime 

Silica 

Alumina 

Oxide of iron 

Magnesia 

Carbonic acid 

Water (combined with lime) 

Svilphuric acid 

Inisolnble and other matters. 



Total. 



Hs - ^ Hs ^ * ^ * 

It must be remembered that much depends upon the physical 
properties of the slags apart from their chemical composition. Sam- 
ples of slag which appear b}^ analysis to give veiy similar results dif- 
fer widely in their behavior when made into cement. The physical 
tension which exists between the ultimate particles of the slag, which 
may be greatly altered by sudden or rapid cooling, either by means 
of the air jet or by immersion in -water, ])\iiys an important iDart in ren- 
dering the slag available for the manufacture of cement; indeed, 
without this sudden cooling even the best shigs are valueless. That 
other considerations besides purely chemical ones infiuence the 
behavior of the slag is shown by tlie following samples of slag sand, 
whic^li when analyzed gave almost identical results, but which when 
treated in the same way and mixed with precisely the same amount of 
lime gave widely dilferent results. Tlu^ composition of tln^ sing.s 
was as follows : 



Ingredients. 



Silica 

Alumina 

Lime 

Oxido of iron 

Soda, potuHli, ot( 



A. 


B. 


24.10 


23.23 


16.30 


15.61 


46.53 


47.10 


0. !I3 


0.7S 


5.04 


5.66 1 



Ingredients. 



Carbonic acid. 
Moi.sturo 



Total. 



0.65 
B.45 

100.0(1 



H. 



0.85 
«. {<8 

100.00 



92 

Tested in the same way, the tensile strength was- 

1 cement to 3 sand. 



A. 


B. 


Seven days. 


Twenty-eight days. 


Seven days. 


Tvp-enty-eight days. 


Pounds. 
326 


Pounds. 
431 


Pounds. 
150 


Pounds. 

2U8 



showing the former to be more than double the strength of the latter. 
Slags coming from the same district, and prepared in a similar way, 
do not, however, vary thus widely in their results ; and the above 
disparity must be due to exceptional circumstances which can not at 
present be accounted for. One of the most important considerations 
with respect to a cement from an engineering point of view is its 
relative reliability and soundness; and this quality can only be 
judged bj^ practical experience in actual work, or by a series of tests 
extending over a considerable period of time. 



p Slag cement is, however, only slow for the first few hours of the 
■/setting process, and it speedily acquires great tensile strength and 
I when mixed with sand is often found to become, after three or four 
days, as strong as Portland cement in as many weeks. The extreme 
fineness of the slag cement, and its toughness and plasticity give it 
important advantages, as compared with Portland cement, when 
used in work under water. These properties adapt it especially for 
tidal work and it has been found that when thus employed, the 
water does not become so muddy as when Portland cement is used, 
which is a ijroof that the cement is less liable to be washed out of 
the mixture. The great fineness of the cement makes a closer and 
more plastic concrete and one not so readily penetrated by the water. 
Pats or blocks placed in water directl}^ thej^ are made harden per- 
fectly and show little or no surface deterioration. 

When slag cement is allowed to harden entirely in the air it behaves 
like any other slow-setting cement, the only thing needful to com- 
plete induration being to keep the materials damp during the whole 
of the time that the water required for the hj^dration is being combined. 

N. B.— Mr. Redgrave's article is decidedly favorable to slag cement, but takes 
special pains to show in many iDlaces that it is not a Portland cement. It gives 
seven tables, showing the results of the test of briquettes, several of which ex- 
tend over a period of six months. 



93 

Appendix 17. 

Extract from ^^Proceedings of Institution of Cicil Engineers,^^ 

England. 

R. ^Y. Mahon: From page 394, vol. 116 (1894), "Proceedings of 
lastitution of Civil Engineers," England; as abridged and abstracted 
from page 184, March, 1894, Journal of Franklin Institute. 

[Extract.] 
SLAG CEMENT. 

Reference is made to the extent of this industry in European 
countries, Germany alone being said to have produced in 1892 600,000 
tons. The blast-furnace slags employed for cement making consist 
of complex basic silicates of lime, alumina, and magnesia, with a 
little ferrous oxide and alkali, and a small percentage of sulphide of 
lime. The cement value of slag is increased by running it into water 
while in the molten state; this may perhaps be due to some change 
in the molecule. The author gives the results of certain experiments 
carried out by him for the Marjdand Steel Company to determine 
the value of their blast-furnace slag for cement making. The lime- 
stone employed by this company, which comes from near Baltimore, 
is of two different varieties, the one containing a low percentage 
(from a mere trace up to 2.48 per cent) of magnesia, the other having 
from 13.15 up to 17.58 per cent of this substance; the former being 
in rather large crj^stals, the latter more compact and composed of 
small crystals. That with the smaller percentage is i3referable for 
cement making. Detailed analyses are given in a table of the differ- 
ent slags employed, and the experiments made with these slags and 
with German, English, and American Portland cements of the best 
quality, by way of comparison, are set forth in a tabulated form. 
The slags were in all cases carefully granulated and ground; the3^ 
were also i)assed through a lOO-mesh sieve. The lime was slaked 
with due precautions and likewise ground. It was of the following 
composition when slaked: 

For cent. 

Lime 61. 44 

Magnesia 2. 04 

Alumina 1 . 88 

Silica 5. 08 

Ferric oxide 0. '22 

Carbonic acid (>. s j 

Water li). To 

97.:5r> 



94 

A suitable mixture of slags consisted of 30.62 per cent of silica, 
1^.94 of alumina, 0.38 of iron, 46.58 of lime, and 3.71 per cent of 
magnesia ; the tests indicate that the best slags for cement making 
are low in silica and high in lime and alumina. Slags containing 
under 30 per cent of silica, and over 47.50 of lime, and 17 per cent 
of alumina have furnished the best results. Lime added to such slags 
in the proportion of 25 parts by weight of slaked lime to 100 parts 
of slag was found to answer best. Some of the slag cements com- 
pare favorably with the Portland cements, as will be seen in the fol- 
lowing table of the results at twenty-eight daj'S, or one day in air and 
twenty-seven days in water : 



Nature of cement. 



TeBsile 

strength 

per square 

inch. 



English Portland . 

Do 

Do 

American No. 1 . . . 

Do 



Pounds. 

2m 

333 
333 

88 
109 



Kept in- 



Dry air. 
Moist air. 
Water. 
Dry air. 
Moist air. 



Nature of cement. 



American No. 1 
Slag cement 

'Do 

Do 

Do 



Tensile 

strength 

per square 

inch. 



Founds. 
79 
375 
210 
253 
353 



Kept in- 



Water. 
Dry air. 
Moist air. 
Water. 
Moist air. 



Another abstract, made in 1900, direct^ from the same article in 
the March, 1894, Journal of Franklin Institute, states that Mahon 
recommends, as likely to improve the resulting jproduct, changes in 
methods as follows : 

Hotter granulation. 

Finer grinding. 

Slaking under pressure. 

More intimate incorporation of materials. 

Selecting materials for slag and lime. 



Appendix 18. 

Extract from United States consular reports^ Slag Cement in Germany; 

Frankfort. 

Frank H. Mason, consul general, Frankfort, Germany, July 3, 
1895: Report to United States State Department, as printed in 
Consular Reports, vol. L, Xo. 185, February, 1896: Slag Cement in 
Germany; Frankfort. Pages 224-228. 

[Full extract.] 
*SLAG CEMENT IN GERMANY; FRANKFORT. 

In response to the instructions of the Department, the following 
information concerning the manufacture, cost, and uses of slag 
cement in Germany is respectfully submitted. 



* Reports in answer to instructions from the Department of State. 



95 

Slag cement is made by mixing pulverized hydrate of lime with 
basic blast-furnace scoria, which has been granulated, dried, and 
reduced to powder hj grinding. It is used for certain purposes as a 
substitute for Portland cement for the reason, primarily, that it is 
about 20 per cent cheaper per ton and being of lower specific gravity 
"spreads farther," weight for weight, than Portland cement, so that, 
taking both points into account, the economy of slag cement may be 
as high as 30 or 40 per cent. It is furthermore claimed that when 
properly made, mortar based on slag cement is more tenacious and 
elastic than that made from other materials, which gives it an advan- 
tage for the foundation of bridges and other constructions which are 
subject to unequal strain and the shock of passing trains and 
vehicles. 

Slag cement seems to have been originally suggested by the excel- 
lent results obtained long ago in Ital}' with mixtures of hydraulic 
lime and " i^uzzolani," or the pulverized lava of v^olcanoes, and was 
first produced industrially in Germany at the Georgemarie blast fur- 
nace in Westphalia about the year 18G3, and the process there em- 
ployed was described in an essay read by Mr. W. Lllrmann before 
the Technical Society at Osnabriick in January, 1807. Blast-furnace 
owners recognized in the new manufacture a profitable outlet for 
the worthless slag that the}^ had been for years piling up on costly 
land purchased for that purpose, and during the next decade many 
of them embarked in the manufacture of slag cement, onl}^ to find 
that their scoria contained elements that unfitted it for that purx^ose 
and that the resulting cement was untrustworthy and worthless. The 
jjreparation of the slag for mixture with the lime was found to re- 
quire careful and exact manipulation. It is granulated b}^ quenching 
with water while in the white-hot fluid condition in which it comes 
from the furnace, and much depends upon the varjang conditions 
under which this part of the operation is performed. 

Several different methods of granulating and preparing the slag 
were invented and patented, among others that of Mr. LudwigRolh, 
a furjiace and mining engineer at Wetzlar, whose process was per- 
fected about the year 1882. lUit it was soon found that the most 
important consideration, upon which all else really depends, is the 
character of the slag itself, resulting from the chemical composition 
of the ore mixture used and the pressure and other conditions umU'r 
wliich the smelting has been elfected. The essential elenuMil in 
basic slag for making cement is its silicic acid, and, this being in 
siiflicieMt proportion, the next(iuestioiisare (1) wlu^ther tliis (Yemeni is 
" live" and in condition to unite readily and firmly with the lime, and 
(2) whether the slag contains a due pro[)ortion of magnesia and not 



96 

an excess of some impurity — sucli as sulphide of calcium or other 
form of sulphur — which will resist this combination and sooner or 
later cause Avork laid in the cement to crtimble and disintegrate. 

Through these unknown difficulties, which in many cases no inge- 
nuit}^ cottld circumvent, the German slag-cement makers, many of 
whom were iDrimarily manufacturers of Portland cement, stumbled 
and labored for years until repeated failures brought rhe whole sub- 
ject into disrepute, and the Portland-cement makers were obliged, 
in order to defend themselves from the suspicion of adulterating their 
product with the cheaper slag cement, to sign an agreement to make 
no more of it. It thus happens that whereas there were in this 
country a few years ago a dozen or more firms that openh' made and 
sold slag cement, there is to-day in western German^', so far as can 
be ascertained, but one small district — in tlie valley of the Saar — 
where slag of perfect ciualit}' for this special purpose is produced, and 
where the slag-cement manufacture is concentrated in the hands of 
two firms of large resources and the highest responsibility. These 
are, respectively, Messrs. Booking &: Dietsch, at Malstatt-on-the-Saar, 
and the Cementfabrik, formerly Erhardt Brothers & Lingenbrinck, 
at Xeunkirchen, a few miles distant from Malstatt. 

The first of these establishments has maintained during the past 
nine j^ears a fully equipped proA'ing station, where its product is con- 
stantly tested and proved by methods that are recognized by exjDerts 
as conclusive. Its cement has been apiDroved and used by the engi- 
neers of Frankfort, Cologne, and other German cities, and it is offered 
for export by Mr. Franz Kirrmaier, of Speyer-on-Rhine, in shipments 
of 50 tons or more at 5.35 marks (81.28) per barrel of 150 kilogrammes 
(330 pounds) free on board at Rotterdam. For smaller orders down 
to 25 tons the present price is 81.10 i^er barrel. In shipiDing bj' rail 
or water the lower specific gravity of slag cement as comp>ared with 
Portland cement causes a noteworthy difference in the space occupied. 
In Germany, where 10 metric tons (22,010 pounds) constitute a car- 
load, this weight of slag cement occupies 10 cubic meters of space, 
while the same weight of Portland cement fills only 7 cubic meters. 

The Cementfabrik at Xeunkirchen is likewise an industrial con- 
cern of high rank, which has labored long and faithfully to bring its 
product up to the highest standard of excellence. It exhibited its 
cement and building blocks, etc., made therefrom at Chicago in 1893 
and gained one of the highest premiums given in that class of mate- 
rials. Its cement has been officially tested at various times and with 
uniformly excellent results by the royal proving station at Berlin 
and the state testing bureau of Switzerland, which is under the direc- 
tion of Professor Tetmajer, one of the foremost of European experts 



97 

in that branch of science. It has been used in the harbor works at 
Olfenbach-on-Main and bj^ jnsmy engineers in this part of Germany 
for substructures of various kinds, and so far as can be learned with 
satisfactory success. For most uses the mixture employed is one 
part of cement to three or four of sand. The firm at Neunkirchen 
does not at present export its product to any important extent, for 
the reason, apparently, that its output finds a residy market at home. 
But its capacity has been recently' so enlarged that it can produce 
on demand a surplus for export, which is packed in double sacks of 
50 kilogrammes each. 

Exact information on some of the points involved by this subject 
are dif&cult to obtain, but from what can be learned the following 
would seem to be a fair statement of the uses and general repute of 
slag cement in Germany. While no competent engineer in this coun- 
try would use slag cement without knowing where, by whom, and 
from what materials it had been manufactured, experience shows 
that it may be employed with advantage when of good quality 
for various purposes, especially the foundations of buildings and 
hj'draulic constructions where the work will be alwaj^s moist and 
protected from the sun. It is not adapted to boiler settings nor as 
an air mortar for brickwork. It is usually mixed in proportion of 
one to three or four with sharp, coarse sand, and when of good quality 
requires about twenty-four hours to set. It is, therefore, often used 
for the foundation of sewers, but it sets too slowly for the upi)er 
work of such constructions. For this latter purpose Portland cement, 
which hardens in from two to four hours, is generally preferred. 

Slag cement is also extensively used for the manufacture of pav- 
ing tiles for sidewalks, railway stations, courtj^ards, etc., and for 
this purpose is mixed with fine Rhine gravel and quartz sand and 
squeezed under 500 tons pressure into square lozenge-marked plates 
of such size that eleven of them cover a square meter (10.8 square 
feet) of surface, the cost of the tiles being 81 cents per square meter. 

The manufacture of slag cement, while requiring thorough techni- 
cal knowledge of good workmanship, involves no serious mechanical 
difficulties. The essential requisite is basic furnace slag of the right 
chemical composition, containing from 30 to 40 per cent of silicic acid, 
and, as already indicated, no cliemical impurity that will resist or 
afterwards undermine the coml)ination that is formed between tlio 
acid and the liydrate of lime upon which the whole strength and 
fabric of the cement depends. Only careful analysis and prolonged 
t(\sts can safely demonstrate that the seoria of any particular blast 
furnace is pcu-l'ectly adapted for this purpose. This having been 
established, and the X)lant erected, the llrsl lesson to be learned is the 
7 



98 

exact method by which that particular slag can be best granulated. 
In this operation, the temperature of the slag when quenched, the 
pressure under which it has been smelted and drawn from the fur- 
nace, the quantity and temiDcrature of the water used, must all be 
taken into account to insure a perfect result. Slag from gray foundry 
pig, smelted under high pressure and as free as possible from sulphur, 
is generally, other conditions being favorable, the best. Roth gives 
in his treatise published in 1883 the following analysis of a slag from 
coke-smelted foundry pig, which yielded good results in the manu- 
facture of cement: Lime, 51.62 per cent; silicic acid, 35.12 per cent; 
argillaceous earth, 8.53 per cent; magnesia, 1.58 per cent; peroxide 
of iron, 0.87 per cent; peroxide of manganese, 0.37 per cent; sulphur, 
0.88 per cent. 

When granulated it is dried and ground to fine powder in what is 
known in Germany as " Gruson mill," but it is thought that Griffin's 
American mill is quite as well if not even better adapted to the pur- 
pose. 

For the information of those who are technically interested in the 

subject there is appended as an exhibit with this report a work of 

the highest authority and recent date by Prof. L. Tetmajer, of the 

Polytechnicum at Zurich and chief of the Swiss Government station 

for testing building materials.* Professor Tetmajer was one of the 

original and strongest advocates of slag cement; he has spent many 

years in exhaustive experiments with all kinds of building materials, 

and he gives in his present treatise the results of his comparative 

tests of hydraulic lime, Portland, Roman, and slag cements under all 

conditions of humiditj^, pressure, and temperature. 

Frank H. Mason, 

Consul- General. 
Frankfort, July 3, 1895. 



Appendix 19. 

Extract from Proceedings of Institution of Civil Engineers^ England. 

Karl Berger : In vol. 128 (1897), Proceedings of Institution of Civil 
Engineers : History of Slag Cement in regard to Expansion, accord- 
ing to Austrian Rules. 

[Extract.] 

The successful results which have occasionally ensued from the use 
of slag cement have induced certain authorities to permit of the 
supply of this material on equal terms with Portland cement. How 

* Professor Tetmajer's publication filed in the Bureau of Statistics, Department 
of State. 



09 

far this may be justifiable is not discussed, but it is pointed out that 
cement of this character should be subjected to special conditions, 
though this is not the case under the Austrian normal regulations 
for the testing of Portland cement. As respects fineness of grinding 
and tensile strength, the Austrian samples of slag cement are capable 
of satisfying all the requirements laid down for Portland cement, 
and in some of these tests the slag cement is so greatly superior as 
to insure its acceptance, but if tested neat it is liable to become hair- 
cracked to a far greater extent than pats of neat Portland, and when 
exposed to the hot-air test, and more especially to the boiling test, 
slag cement often gives very unsatisfactory results. The cracking 
of the pats exactly coincides with the effects observed in the case of 
over-burned, hot cements, and the causes of this cracking at the 
edges of the pats in the case of slag cement are considered. 

It is frequently found that, in contradistinction to the experience 
with Portland cement, a slag cement which proves imperfect when 
tested neat will give very satisfactory results when tested with three 
parts of standard sand. Tlie expansion is probably caused by minute 
particles of imperfectly slaked lime, which, owing to the extremely 
fine grinding in the case of the neat slag cement, find no sjDace for 
increase of bulk, and thus lead to disrupture, whereas when used 
with sand the cavities between the sand grains afford sufficient space 
for the increase of volume in the cement. 



Appendix 20. 
Extract from Engineering and Mining Journal. 

A. D. Elbers: In October 30, 1807, Engineering and Mining Jour- 
nal, reviewing article by Henri d'Etieune in September, 1897, Revue 
Universelle des Mines : Manufacture and Properties of Blast-furnace 
Slag Cement. 

[Extract.] 

Under the above caption the September number of the Revue 
Universelle des jVIines brings an essay of sixty pages b}'' Henri 
d'P]tienne, a member of the engineering staff of the Societe John 
Cockerill, at Seraing, in IJelgium. The essay is well written. It con- 
trasts favorably with the jumbled aiul unwarranted statements on 
the same subject which were editoriallj'" criticised in the Engineering 
and Mining Journal of June 1, 1805, and still more so with certain 
otln^r outgivings on this subject. 

The slag cement, which Mr. (rEtienne describes, consists of granu- 
lated basic slag which has been heated to dryni^ss and then ground 
fine in admixture with, say, from 15 to 20 per cent of Tat dry-slaked 



100 

lime. The basic slag is considered suitable for this purpose when it 
lias its essential constitutents within the following limits : SiOo 27 per 
cent to 32 per cent, AloOg 12 per cent, to 22 per cent, CaO 49 per cent 
to 55 per cent. The granulated slag is apt to give the best results 
when it has been dried by heating it to about 500° C, or to a dark 
red heat, and this operation involves a consumption of coke amount- 
ing to about 9 x)er cent of the weight of the dried slag. The com- 
minution of the dried granulated slag requires from 25 to 30 horse- 
power, for the i^roduction of from 450 to 800 kilogrammes of slag 
meal per hour. The slag meal is passed through a Xo. SO metallic 
sieve (76 meshes to the linear inch) and is then so fine as to leave only 
from 10 to 12 i3er cent residue on a sieve of 180 meshes to the linear 
Inch, and sometimes less than 8 per cent. The lime is slaked by 
immersion, care being taken to have all superfluous water drop off, 
so that the slaked mass becomes thoroughlj^ pulverulent. The slaked 
lime has to be kept stored from 8 to 10 days in order to render it so 
completely dr}' that it will pass easily through a No. 80 sieve, but as 
it usually still contains from 2 to 5 per cent of incompletely calcined 
stone, it is first passed through a coarse screen. 

After the raw materials have been thus prepared they are dry- 
mixed in suitable proportions and the mixture is put up in bags and 
barrels read}' for use as blast-furnace slag cement. Strictly speak- 
ing, this is not a cement, but a cement mortar. From the very nature 
of its composition it becomes evident that its ultimate hardening 
properties must be inferior to those of Portland cement, or, for that 
matter, even to those of good natural cement, such as Rosendale, and 
that its capacity of hardening under water must be inferior to those 
of trass, santorin, and puzzuolana, whereas its property of harden- 
ing in the dry state must be somewhat similar to that of common 
"air mortar," using that term in contradistinction to "hydraulic." 
Nevertheless, it must be admitted that the system of manufacture 
which Mr. d'Etienne advocates appears to be about the most perfect 
that can be devised for bringing out the best properties of a material 
that suffers from an insuperable defect, viz, from the vitiating in- 
fluence of its contents of soluble sulphides. As has been shown in 
previous articles, this influence can be overcome by proper treatment 
in the case of less basic slags, but these less basic slags have no setting 
properties and can only be used as "silicifiers," whereas those slags 
that are setters can not be imi^roved by the treatment referred to. 

Mr. d'Etienne disposes, on page 277, of this sulphide qtiestion in 
the following manner: 

As regards sulphides, the slag does contain some, especially when the furnace 
is working hot. The granulation decomposes a part of them, hut the granulated 
slag as it is used in the manufacture of the cement still contains from 1 to 3 per 
cent of sulphur in the state of MnS, CaSO^, and CaS. It would seem that the CaS 



101 

transforms itself by contact with the water that is used in ganging the cement 
and in presence of ferric oxide into calcium hydrate, under production of ferrous 
sulphide (FeS). It is this latter sulphide that imparts the greenish tint which is 
observed on the fractured surfaces of fresh briquettes that are made of blast- 
furnace slag cement. In contact with the air the ferrous sulphide oxidizes and 
then the greenish tint of the fractures become bleached. There is no reason to 
fear deterioration on that account, because briquettes that are four years old have 
thus far not undergone the least alteration in volume or texture, in spite of the 
intensely greenish tint of their fractures. 

Now, with all due respect for the objective manner in which Mr. 
d'Etienne has treated the mechanical part of the process, it must be 
said that his chemical deductions in regard to the behavior of the 
calcium suli^hide contents are rather stunning. 

The fact of the matter is that tlie slag he speaks of contains the 
greater pai*t of its sulphur in the form of calcium sulphide ; that the 
granulated ^lag still contains several per cent of the latter, even 
under the most favorable circumstances; that not one-twentieth part 
of these sulphide contents can become transformed by the reactions 
that take place in gauging or that result therefrom, inasmuch as those 
reactions are merely, superficial, and that the dissolution of one-hun- 
dredth part of the contained calcium sulphide would suffice to impart 
to the cement fracture that greenish tint whicli he assumes to be an 
indication that all of the CaS has transformed itself. Moreover, 
there is no reason why a briquette made of tliis sulphurous cement 
should have undergone any alteration in volume or texture on account 
of being four years old; but if it had been kept for that length of 
time under water, or if it had been frequently subject during that 
time to varying atmospheric influences, then its strength would be 
found to have diminished with age. 

It is probably for such reason that the administration of public 
works (des Pouts et Chaussees) lias tlius far refused to accept blast- 
furnace slag cement (as Mr. d'Etienne frankly states), and it is not 
likel}^ tliat such a material will ever be mentioned in the specifica- 
tions of any constructor who is competent to judge of its chemical 
properties. On the other hand, such cement is apt to find its way 
readily into almost any kind of structure in a surreptitious manner 
as an adulterant of Portland cement, and in that way it is apt to do 
frequently more harm tlian if it were used knowingly. 

Of the many interesting experiments which Mr. (TEtienno recounts 
in liis essay, I only mention tlie results ol)tained by admixing blast- 
furnace slag cenuint with small ([uanlities of soda. The time of 
setting is tli(M-eby considei'ably reduced, and tlu» rapidity o[' the 
setting increases — within a range of from 1 i)ei' cent {o'l\ percent — 
ill proportion to the <[uanl ity of tlie admixture, in practice it is found 
that an admixtui-eof froni ! { per cent to 1,1 [)er cent of Na.XH);, gives 
the best results. 



102 

Whatever fault maj^ be found with some of Mr. d'Etienne's con- 
clusions on the general merits of the described manufacture, it must 
be admitted that he presents most of the facts and arguments in such 
an open manner that no one who is conversant with the chemistry of, 
cements can be misled by them. 



Appendix 21. 



Extract from '^ The Utilization of Blast-furnace Slag and its PossT] 

hilities,^^ Elhers. 

Alex. D. Elbers : From pamphlet published by author at Hoboken 
N. J., October, 1898: "Utilization of Blast-furnace Slag and its Pos 
sibilities." 

[Extract.] 

The manufacture of so-called slag cement, a comiDOsition that con- 
sists of granulated slag that is first dried then ground fine and mixed 
with iDulverized slaked lime, and in some cases with a small propor- 
tion of soua, has also a precarious existence, chieflj^ on account of 
the shortcomings of the product. 

The most essential characteristic of a true hj'draulic cement is its 
inherent setting propert}^, or, to put it in another way, the capacity 
of its constituent silicates to hydrate without undergoing an 3^ material 
change in volume. Very basic or subsilicate slag has only feeble 
setting capacity and the less basic usually has none. The "set" 
of the slag cement is, therefore, chiefly dependent on the reactions 
of the admixed lime. As soon as the cement is gauged some of the 
lime dissolves ; the dissolved lime reacts on the slag particles, extracts 
from their surfaces small portions of gelatinous silica and combines 
with them, and the resulting new compounds, which are also at first 
in the gelatinous state, agglutinate the mass and in hardening 
gradually cement it more firmlj". A small admixture of soda is apt 
to intensify these cementitious reactions, partlj" because it prevents 
the gelatinous compounds from drjdng out too quickly during the 
setting, and also because it acts as a bearer of gelatinous silica to the 
lime when the set mass is kept immersed. The setting progresses, 
nevertheless, rather too slowlj^ 

The main technical objection to such slag cement is, however, its 
sulphurous condition. 

All blast-furnace slag that is easily reacted u^Don hj lime carries 
usually several per cent of calcium sulphide in inter molecular com- 
bination, which means that each particle of the slag, however small, 
contains it in about the same proTJortion. In the gauged slag cement 
this impurity- dissolves to the extent to which it crops out on the sur- 
faces of the slag j)articles, while the aforementioned reactions of the 

■ 



103 

lime are progressing, and thus becomes mixed up with the forming 
cementitious matter. The amount that goes actually into solution 
averages probably not over o per cent of the total contents, but the 
amount of the silica that becomes dissolved by the lime is also, com- 
parativel}", insignificant ; hence the forming cementitious compounds, 
on the gradual induration of which tlie ultimate strength of the mass 
depends, are apt to become as sulphurous as the crude slag is, if not 
more so ; and the consequence of this condition is that the ai)plied 
cement becomes liable to subsequent disintegration, which sometimes 
may only set in after the lapse of years. 

The aforementioned slag stones are comxjaratively free from this 
defect because the granulated slag — which enters their composition 
without further comminution — becomes, to a certain extent, suxDer- 
ficially desulphurized during the process of granulation by the action 
of hot water and steam ; but the slag that is made up into cement is 
ground fine after granulation ; hence, the surfaces of its i^articles are 
nearly as sulphurous as their interior. Nor does the drying at a 
comparatively high temperature have any appreciable effect on the 
sulphurous interior of the granulated particles. Further details of 
the process, as carried out at Seraing, in Belgium, can be found in 
"Notes on the Manufacture and Preparation of Blast-furnace Slag 
Cement," published by the Engineering and Mining Journal in its 
issue of October 30, 1897. 



Appendix 22. 

Extract from Transactions of American Society of Civil Engineers. 

R. W. Lesley: In pages 513 et seq., vol. 37, Transactions of Ameri- 
can Society of Civil Engineers : Slag cements. 

[Extract.] 

Large quantities of slag cement mentioned by Mr. Gold mark were 
made in Germany about 1885. Investigations of the process and tlie 
product in this country had much the same results as he mentioned; 
the results of long-time tests w^ere failures. A United States con- 
sular report (dated July 3, 1895) states that out of about fifty slag 
cement works in Germany in 1890 only two were then in oi)eration, 
from whicli fact tlie growth of tlie industry in America can be pre- 
dicted. The chemical difficulty of the process is the presence of sul- 
phides in slags, and until some reliable metliod of dealing with (Iumu 
is devised no good uniform slag cement will be made. 'J'he practical 
difficulty is that no om^ making first-class iron or steel will laj' much 
weight on the kind of slag he is tuniing out, and Portland eenuMit is 
too ini[)oi'taMt in its uses to be dependent for its manufacture upon 
the production of a iniiforin by-[)ro(luct of another industry. 



10^ 



Appendix 23. 

Extract from Engineering News. 
S. B. Russell, November 23, 1898: In iDages 418 et seq., December 
29, 1898, Engineering Xews : Results of Tests of a Hydraulic Cement 
Containing a Large Percentage of Sulphides. 

[Extract.] 

Sir: Herewith I send you a table of tests made with a certain 
brand of American cement, the name of which is withheld. The 
cement was bought on specifications which required a certain tensile 
strength after one day in air and six days in water, also a certain 
fineness on a No. 100 sieve. The samples taken xDassed the tests 
given and the cement was accepted. The usual test for change of 
volume showed no defects as noted under remarks in the table. The 
sand tests also were good. The percentages of sulphuric acid and 
magnesia were thought to be low enough but the high proportion of 
sulphides caused the cement to be looked on with suspicion. The 
cement was therefore used in comparatively unimportant work. 
Part of the cement so used took a fairly good set, but part of it failed 



to get hard. 



It was found to 



but if allowed to dry would lose a great 



Further tests were then made with the cement, 
take a good set in water 
part of its strength, as may be seen from the table. For exam^Dle, 
10 briquettes were put in air one day, then left in water for six daj^s, 
then removed from the water and kept in a damj) atmosphere at a 
moderate temperature for seven days more before breaking. These 
briquettes showed a strength (Table 1) of only 158 pounds per square 
Inch. 

Table 1. — Results of experiTnental tests of a defective hydraulic cement. 





Date. 


Number 
of bri- 
quettes. 


In air. 


Days— 

In 
water. 


In air. 

■ 


Tensile strength. 


X umber. 


Maxi- 
mum. 


Mini- 
mum,. 


Aver- 
age. 


1 


1898. 
July 27 
Au^. 18 
....do... 




r 
-I 


6 
6 
27 
6 

1 

6 
6 







5 


1 

I' 


Pounds. 
564 
232 
382 
614 
240 
254 
482 
286 
182 


Pounds. 
352 
196 


Pounds. 
*443 


o 




+213 


3 




300 t34n 


4 


Oct. 3 
. . . . do . . . 


10 
10 
10 
10 
10 
10 


412 
152 
184 
368 
224 
136 


496 


5 


203 


6 


....do... 


229 




.... do . . . 


i451 


8 

9 


Oct. 26 
....do... 


258 
158 



*Pats O. K. +Sand test— 1 cement. 3 sand— pats O. K. i Briquettes swollen slightly. 

Note.— Fineness=94.8 per cent on No. 100 sieve; magnesia (MgO)=2.25 per cent; sulphiiric 
acid (SOa^^trace; siilphur as sulphide CS) = 1.21 per cent. All samples were from the same lot 
of 120 barrels. 

The experiments, Nos. 4-7, under date of October 3, were made 
simultaneously with similar tests of Atlas American Portland and 
German puzzolan cement. In these tests with the Atlas cement the 



105 

highest result obtained was 854 pounds after one day in air and six 
days in water; the lowest was 765 pounds after seven days in air 
only. With the puzzolan the highest was 455 pounds after one day 
in air and six days in water, while the lowest was 435 pounds after 
seven days in air only. Each result was the average of ten bri- 
quettes. Hence, we may say that the Atlas and puzzolan cements do 
not show an important falling off in strength when removed from 
the water. 

There seems to be no satisfactory explanation for the loss of strength 
shown in the table, unless one can be found in the high percentage 
of sulphides, and that does not seem probable. The moral of the 
above account is that th« usual tests of hydraulic cement do not 
always serve to exclude an inferior brand. The matter is thought 
to be worthy of space in your journal, as it may prove a valuable 
hint to those preparing specifications for important work. 
Very truly, yours, 

S. Bent Russell, 

M. Am. Soc. C. E. 
St. Louis, Mo., Nov. 23, 1898. 



Appendix 24. 

Extract frcnn Engineer mg Neios. 

n. J. Livingston, December 31, 1898: In pages 27 et seq., January 
12, 1899, Engineering News: Ilydrciulic Cements Containing a Large 
Percentage of Sulphides. 

[Extract.] 

Sir: Referring to a letter in your issue of December 29, 1898, on 
the above subject, by Mr. S. Bent Russell, the explanation of the 
behavior of tlie cement he refers to is clearly indicated by the data 
he supi)lies, and if, as appears to be the case, the cement was one 
made from waste-iron slag, the matter is plainer' still, for then the 
action of an appreciable quantity of caustic lime is to be reckoned 
on as helping forward the disintegration materially. 

But taking the figures as Mr. Russell gives them, wo have, first, 
quite as much magnesia as is wanted for a cement of the Portland 
class, and, second, we have an excess of suli)hiir, more than enough 
to ruin any such cement. 

In Europe, after forty years' trial, these cements liigh in sulphides 
have found no favor. They often give I'air results when usiul entirely 
under water, foi- ther(3 the suli)hi(les ai*e protected from oxygen, but 
they ar(5 unti'ustworthy if exi)()sed to the free air. The only riuniMly 
is to redu(!e the objeetionabh^ ('actors to reasonable limits, which is 
not a difficult operation, but it must not ho donc^ on ])ai)(M' o\\\y. 



106 

A cement liigli in sulphides will often, if new and kept in water, 
pass the ordinary Portland test, but a chemical analysis will indicate 
accurately what may be expected of it at no very distant date. 
Very respectfully, 

H. J. Livingston. 
Baltimore, Md., Dec. 31, 1898. 



Appendix 25. 

Extract from Engineering Record: Slag Portland Cement. 

Engineering Record, June 21, 1899, pages 83 et seq. : Slag Portland 
Cement. 

[Extract ] 

The following communication has been received from a gentleman 
engaged in cement manufacture, although in no way interested in 
slag cements. The substance of the communication is that the term 
"Slag-Portland" convevs a distinction without much difference. 

The descriptive term "Portland" applied to cement is simply an arbitrary 
name for an artificial mixture. * * ^ 

A German chemist formnlated the first scientific theory of the action of ingre- 
dients contained in cement. Eliminating all mystery of its manufacture he 
showed that Portland cement could be made anywhere and from a variety of 
materials abundant in many localities. Reid, in his treatise on cement, says: 
' ' Wide as the field of selection is from which may be obtained all the necessary 
materials for the manufacture of Portland cement in the various geological for- 
mations and which may be regarded as the natural supply, there are still to be 
found valuable supplies of an artificial character, of which we may select as most 
noteworthy the slags of various kinds resulting from iron making and other 
allied industries. The analysis of this slag is usually favorable as a cement- 
making agent, from the high percentage of the lime it contains." 

A few progi^essive capitalists in the United States, realizing the possibilities of 
utilizing the by-product of blast iron furnaces, have gone into the manufacture 
of a cement therefrom which is proving of excellent quality. For this cement 
production there are well- equipped works in New Jersey, Pennsylvania, Mary- 
land, Ohio, and Illinois. The article made in most of these mills is far superior 
to the foreign substance manufactured from similar sources, which for years has 
been depreciating in reputation and so prejudicing the minds of engineers in this 
country against its use. 

Furnace slag is decarbonized limestone. This limestone rock placed in the 
furnace to fuse "^'ith iron is often taken from the same limestone quarries that 
furnish other rock which is put into Portland cement kilns. In one instance the 
limestone is burned to cinder ; in the other case it is calcined to clinker. In both 
processes the carbonic acid is eliminated from the rock. The main difference in 
the results is the proportion of impurities left therein. Both slag cinder and 
cement clinker, when emerged from their fiery trial, retain some detrimental 
qualities. But both contain the same essential elements of a good cement, though 
in different proportions. There are foreign substances in both that are inert 
which of themselves have no cementing value, but in Portland cement are 
allowed by architects and engineers without debarring the brand from admit,, 
tance into competition with accepted standards. Just how the best Portland 



107 

cement is doctored varies with the different manufacturers, yet all of them do it. 
It is conceded by expert engineers of the highest authority that ' ' there may be 
added foreign material up to 2 per cent of the weight without necessitating any 
change of name." 

By a proper treatment the slag cinder is mixed with such necessary ingredients 
as will produce a cement comparing favorably with any other good brand called 
by whatever name. A comparison of the chemical constituency of both sub- 
stances before and after decarbonization will be instructive to many persons. 
The following analyses show the average and fairly representative proportion of 
constituent elements of raw material in furnace slag and limestone rock. Slag 
has silica 29.96, alumina 10.45, lime 50.40, magnesia 3 35, sulphur 1.44, with traces 
of alkalis; Portland cement rock has silica 14.73, alumina 5.57, lime 70.34, mag- 
nesia 4.47, iron 2.98, and traces of sulphur. 

As a resultant cement after proper calcination and mixture with adulterants, 
the accompanying statement is approximately accurate for a good Portland 
brand: Lime 60 1, silica 23.16, alumina 8.5, ferric oxide 5.3, with less than five 
parts of magnesia and sulphides. 

The chemical composition of a properly made slag cement of domestic manu- 
facture will vary in these proportions : Lime 48 to 55 per cent, silica 23 to 28 
per cent, alumina 10 to 18 per cent, a trace of iron oxide and the balance of 
ingredients — sulphur, potash, soda, and magnesia — not exceeding 7 per cent. 

It should make little difference what name is given to a cementitous substance 
if the desired purpose is satisfactorily accomx^lished by its use. If a slag cement 
in a briquette made according to requirements of the American Society of Civil 
Engineers will show 200 pounds tensile strain in twenty-four hours, 500 pounds 
in seven days, and 700 pounds in three months, surely it may be considered of 
good construction material. These figures are kno^yn to the writer as the results 
of one good brand of slag cement made in the United States. Ordinary imported 
Portland seldom averages better. This for neat cement; sand tests are still 
higher in proportion. With a mixture of one part slag cement to three parts 
sand a resistance is obtained of 200 pounds in seven days and 350 pounds in 
ninety days. This is a good showing for a cement that some prejudiced minds 
refuse fellowshiping with Portland. 



Appendix 26. 

Extract from Engineering Record: The Distinction between Slag and 

Portland Cements. 

Fi'om editoi'ial columns, pages 118 etseq., July 9, 1898, Engineering 
Record: Distinction between Slag and Portland Cements. 

[Extract.] 

It is a somewhat surprising feature of tlie cement trade in the 
United States just at present tliat dealers in the puzzuolana or shig 
cements manufactured here, instead of i)laeing theiu on \\\o market 
as such, like the merchants of Europe, are endeavoring lo sell I hem 
as Portland cements. I^ortland cement is a term which has aniuired 
a definite^ meaning, and a slag cement does iH)t fall 'under it unless 
it is distorted. An attempt to sell slag cement as Pt)rtland is bound 
to result injuriously to tlie former material I'oi' two reasons. The 



108 

first is that the average purchaser of a cement spiel him as a Port- 
land will be uneasy when he learns, as he certainly will, the material 
is reallj^ a slag cement; while the second is that the manufacturers 
of slag cement will find that the good qualities their article develops 
in service will not be attributed to their product solelj^, but rather to 
Portland cement in general ; in other words, thej^ are depriving them- 
selves largely of the prestige won by their special grade of cement. 
As the distinction between the two materials is an important one, 
"The Engineering Record" prints herewith an article on the subject 
by an experienced manufacturer of cement. 

The manufacture of slag cement is beginning in this countr}', and 
while the industry in Germany and in Europe generally has almost 
ceased to exist, the material is coming into use on work here.* In a 
recent award of a large contract, the question came up as to whether, 
under a specification calling for Portland cement, a slag cement 
could be delivered. The cement in question is admittedly made of a 
mechanical combination of slag and slaked lime; therefore it is 
claimed not to be a Portland cement, answering the requirements of 
sjDecifications and the well-known definition of Portland cement 
current in scientific literature and also among cement dealers and 
manufacturers. In connection with the protest filed against the use 
of slag cement under the name of Portland cement, it is proper to 
call attention to the several differences between slag and Portland 
cements, and the definitions of the authorities on the two materials. 

In a work published by direction of Gen. Wm. P. Craighill, late 
Chief of Engineers, U. S. Army, Washington, Government Printing 
Office, in 1896, giving the results of congresses held at Munich, Dres- 
den, Berlin, and Vienna for the purpose of adopting uniform methods 
for testing construction materials, which conventions were attended 
by representatives of the leading governments of Europe and America, 
on page 38, under the head of nomenclature, are found definitions of 
six hydraulic binding materials. In paragraph 3, Portland cements 
are defined to be "products obtained from the calcination up to the 
verge of vitrifaction of natural marl, or of artificial mixtures of sub- 
stances containing clay and lime. They are reduced to powder and 
contain at least one-seventh by weight of lime for one part of the 
material which gives to the lime its hydraulic property. To regulate 
certain properties of technical importance, there may be added 
foreign material up to 2 per cent of the weight without this addition 
necessitating any change of name." Under paragraph 4, hydraulic 
admixtures are defined to be "natural or artificial materials which 

* It is the belief of ' ' The Engineering Record " that the fact that German manu- 
facturers have been unsuccessful in making slag cement is no proof American 
technologists will fail in such an industry. 



109 

generally do not harden under water when alone, but only when mixed 
with caustic limes. Such are puzzuolana, santorin earth, trass ob- 
tained from certain volcanic tufa, furnace slag, burnt clay;" and in 
paragraph 5, "puzzuolana cements are products obtained b}^ inti- 
mately mixing powdered hydrates ol lime with hydraulic mixtures, 
ground to the fineness of dust." 

Thus on the authority of the highest body of scientists in the world 
in the line of testing construction materials, and approved b}^ the 
Engineering Department of the United States Government, slag 
cement is not a Portland cement, but is puzzuolana cement, clearly 
and distinctly. This general broad distinction between slag cements 
and Portland cements is followed in all the specifications of the 
various governments of Europe. In France, under the report of the 
Commission des Methodes D'Essai of the materials of construction 
in the Department of Public Works, Paris, published in 1804, the 
same distinction is drawn between slag cement and Portland cement, 
the two ingredients being treated in separate chapters of the book, 
the one under the head of "Cement" on pages 248 et. seq., and the 
other under the head of "Puzzuolana" on pages oS'-Zet. seq. On i^age 
254 of this work it is stated : "The specific gravity of different kinds 
of cement present sufficient differences to be clearlj^ noted. One 
could not confound, for instance, a Portland cement of which the 
density should oscillate about 3.10 with slag cement of which the 
specific" gravity can not exceed 2.85." 

On page 332, after speaking of natural puzzuolana, it states that 
as to "artificial puzzuolanas outside of the materials which, like the 
slags, enter into the composition of products sold and tested conse- 
quently under the denominations of cement, they present no serious 
interest to the constructor." 

The leading authoritj^ on slag cement in the world, Professor 
Tetmajer, in his works published in Zurich in 1893, is clear in the 
distinctions he draws between it and Portland cement, for after 
defining Portland cement as shown above in the convention of tlie 
Congress of Tests of which he is president, he states that "puzzuo- 
lana cements are products w^liicli are obtained by the intinuite mix- 
ture of slaked lime in powder with liydraulic materials finely i)ul- 
verized," and refers especially to the slag cement as a species of 
puzzuolana cement under which he definitel}^ classes it. The same 
dermiliou and distinction is made in (lie English works writltMi l)y 
Redgrave, London, IS'.):), and in lledgrave's i)aper bol'ori^ the Insti- 
tution of Civil Engineers, London, in 1890 antl 1S91, vol. C\*. So, 
thenvCon^, on th(U)road proposition it is clearly shown that in France, 
England, and (icrmany, and in the United Stales by (he pnblieation 
auihorizc^d l>y (ieneral Craigliill, there is a distinct antl absolnle dil"- 



^ 



110 

ference, well recognized, between slag cement and Portland cement. 
The weight of authoritj^, therefore, being as to this material differ- 
ence, it is interesting to take the definition of the varions specifica- 
tions of the world and see what a Portland cement is and how far a 
slag cement falls within its lines. By the specifications of the U. S. 
j^avy Department, Bureau of Supplies and Accounts, approved July 
6, 1896, specification for Portland cement, the specific gravity shall 
not be less than 3 and the material must have its final set at the end 
of eight hours. By all the authorities above referred to, as well as 
Schoch on Mortar Materials, Berlin, 1897 — Candlot, Heath, Redgrave, 
Spalding, Tetmajer, and other writers — slag cement has a specific 
gravity of from 2.7 to 2.8 and attains its final set in from twelve to 
twenty-four hours. Thus under the specification of the United States, 
slag cement is not a Portland cement. 

In the French specifications of the Ponts et Chaussees, Portland 
cement is defined to be "the product of the grinding of clinkered 
rock obtained by the burning to a point of softening of an intimate 
mixture of carbonate of lime and argillaceous matter, rigorously 
combined and chemically and physically homogenous in all its parts." 

By the standard tests accepted by the German government in a 
decree of the Minister of Public Works dated July 28, 1887, Portland 
cement is a material resulting from the calcination, carried to the 
point of incii3ient fusion, of an intimate mixture of lime and argilla- 
ceous substances as its essential components; such calcination being* 
followed by the grinding of the product to the fineness of flour. 

In Switzerland, Portland cements are described to be the product 
obtained by the burning to the point of vitrification of hydraulic 
lime, stones, or of mixtures of argillaceous and calcareous materials, 
which are subsequently ground and reduced to fine powder. Port- 
land cement in addition must contain a minimum of 1.7 parts lime 
to the unity of hydraulic materials. 

In Austria, in the specifications of the Austrian Engineers and 
Architects' Association, 1890, Portland cement is defined to be "com- 
pounds of natural marls or artificial mixtures of clay and lime-bear- 
ing materials which are burned to vitrification and are subsequently 
ground to great fineness, and in which the calcareous material shall 
at least be 1.7 to the unity of the argillaceous." 

In Russia, the Minister of Roads and Railways defines Portland 
cement to be "a product made out of natural marls or artificial mix- 
tures of materials in which clay and carbonate of lime are contained, 
and which materials are subsequently burned to clinker, and are 
thereafter ground to the fineness of flour." 

In the English specification quoted with approval on page 290 of Dr, 
Schoch's book, Portland cement is described to be "an intimate mix- 



I 



Ill 



ture of carbonate of lime and clay, which shall have been burned 
together without any foreign material, and it shall have been ground 
to great fineness." 

In all these definitions of Portland cement it will be noticed that 
running through the whole line are certain definite requirements, 
and the best waj^ to show^ the diif erence between Portland cement and 
slag cement is to i)lace in parallel columns the principal elements of 
difference. 

Under the facts above given and the material differences shown, it 
seems hardly necessary to add any further facts to prove that slag 
cement is not Portland cement, even though the label on the top of 
the barrel may say it is. The industry is a new one in this country, 
but is an old one in Germany, and from Consular Reports to the 
State Department, 1895, pages 224 et seq., it will be seen from the 
reports of the consuls at Frankfort, Magdeburg, and Dusseldorf , that 
the slag industry, which was successful there in 1890 and thereabouts, 
has steadily dwindled away, until to-day there is but a single works 
in existence in Germany, and Candlot, referring to this industry, 
states that no new works have been built in Switzerland, while in 
Belgium but one remains, and in France there are but three It 
would therefore seem to remain for. the slag-cement manufacturers 
to explain why it is that if slag cement is as good as Portland cement, 
it is sold in this countrj^ not as slag cement, but as Portland cement, 
while all imported slag cement coming here is labeled puzzuolana 
cement. 

Table showing difference betiveen Portland and slag cements. 



Portland cement- 



Is a mechanical admixture of argillaceous 
and calcareous substances ground together to 
great fineness, made into brick or other forms 
and subsequently chemically acted upon by 
the fire of the kiln in its ])urning to incipient 
vitrifaction. The (blinker thus produced is 
ground to iraimlpable powder. 

The specific gravity of Portland cement ia 3 
to 3.10. 

Thf chemical analysis of Portland cement 
runs from HS to (13 of lime, and the lime 1.7 to 
the unity of the other ingredients. 



Portland (tement sets in one-half lunir to a 
maximum of eight hours. 



Portland cement is absolutely safe to use in 
air. 



The ."ulphuric. acid in Portland comont is 
limited to ^ per cent and is always fouiul as 
sulphate. 



Slag cement- 



Is a mechanical mixture of slag and slaked 
lime, merely ground together mechanically to 
impalpable powder. 



The specific gravity of slag cement is from 
2.7 to 2.S5. 

Slag cement, according to Redgrave's iiapor, 
Institution of C'ivd Enginoors, i)ag»5 7, runs 4(5 
in lime. Other analyses in tho books of Cand- 
lot, Tetmajer, Schocli, and others, sliow simi- 
lar dist;repaucios in analysis between slag and 
Portland cenKMit and the relative shortage of 
lime in the slagcenuMit. 

Slag cemi'nt. according to Tetmajer and 
(\in<llot, takes frt)ni eight to t(Mi hours, and 
sometimes very much longer, for the pure ce- 
ment to set. 

Slag cement, according to Candlot, in his 
reference to Tetma.jcr's work, ami uct'cn'ding 
to 'i\>tmii,i(>r, llt>Mth, and Sialding, will crack 
and have little strengtii in air. 

The sul 1)1 Ulrica ("ill in slag ciMuents frequently 
runs from ;{ to 4 per cent and is oftiMi found us 
sulphide, a most duugorous iugredieut. 



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